When a person tries to induce a fire on an object by focusing sunlight using a concave mirror, the object should be placed at the focal point of the mirror. Concave mirrors have a curved surface that reflects light inward, converging the rays to a single point called the focal point.
In this scenario, the sunlight acts as a source of parallel rays that are reflected off the concave mirror's surface. As these rays converge, they create an intense concentration of heat at the focal point. By placing the object at this location, it will receive the maximum amount of heat energy from the focused sunlight, increasing the likelihood of ignition.
To find the focal point, one can use the mirror's focal length, which is the distance between the mirror's vertex and the focal point. The focal length is typically provided by the manufacturer or can be experimentally determined. It is essential to ensure that the mirror is correctly aligned with the sunlight, so the rays are parallel to the mirror's principal axis to achieve optimal focus and heating.
In summary, to induce a fire on an object using a concave mirror, the object should be placed at the mirror's focal point, where the sunlight's rays are focused and heat is maximized. Proper alignment of the mirror with sunlight and knowledge of the mirror's focal length is crucial for a successful ignition.
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6. An airplane flying at a velocity of 900 km/h [W] travels 400 km west. How long will the plane
be in flight?
Answer:
Explanation:
0.44
N industrial customer with a three-phase, 480 V service entrance is running the following set of loads: • Two 15 HP, 89% efficient lathes, 0. 79 lagging power factor • One 7 ton heat pump' with a COP of 1. 9 and a 0. 95 lagging power factor • Two electric autoclaves, 30 BTU/h, 98% efficient, 0. 97 lagging PF One 25 kW high-intensity discharge (HID) lighting system, unity PF If the lighting system is replaced with a T8 fluorescent system with magnetic ballast that consumes 25% less than the previous system, but introduces a 0. 91 leading power factor, by how much does the service entrance current change? Consider the case when all systems are fully loaded. Consider the AC load under the new lighting regime. Use the NFPA 70 to determine the minimum allowed gauge of the service conductors. Feeder lines are copper, with a 60 °C temperature rating, contained within a raceway with an ambient temperature of 40 °C. Start with article 310. 15; state the specific article(s)/tables used to determine your answer
The minimum allowed gauge of the service conductors would be 1/0 AWG.
To calculate the current at the service entrance, we need to calculate the total power and power factor of the loads.
For the two lathes, the total power is 2 x 15 HP x 0.89 = 26.7 kW, and the power factor is 0.79 lagging. The apparent power (S) can be calculated as S = P / PF = 33.8 kVA.
For the heat pump, the total power is 7 ton x 12,000 BTU/ton x 0.2931 kW/BTU / 1.9 COP = 2.64 kW, and the power factor is 0.95 lagging. The apparent power can be calculated as S = P / PF = 2.78 kVA.
For the two autoclaves, the total power is 2 x 30 BTU/h x 0.98 / 3.412 BTU/kW = 17.5 kW, and the power factor is 0.97 lagging. The apparent power can be calculated as S = P / PF = 18.0 kVA.
For the HID lighting system, the power is 25 kW and the power factor is unity, so the apparent power is equal to the real power, S = P = 25 kVA.
The total apparent power for all loads is S_total = 33.8 + 2.78 + 18.0 + 25 = 79.58 kVA.
If the lighting system is replaced with a T8 fluorescent system that consumes 25% less power, the new power is 0.75 x 25 kW = 18.75 kW. The power factor is 0.91 leading, so the apparent power is S = P / PF = 20.6 kVA.
The new total apparent power for all loads is S_total = 33.8 + 2.78 + 18.0 + 20.6 = 75.18 kVA.
The current can be calculated using the formula I = S / (sqrt(3) x V), where V is the line voltage (480 V):
For the original loads, I_original = 79.58 kVA / (sqrt(3) x 480 V) = 96.4 A
For the new loads, I_new = 75.18 kVA / (sqrt(3) x 480 V) = 91.0 A
Therefore, the change in service entrance current is (91.0 - 96.4) A = -5.4 A.
To determine the minimum allowed gauge of the service conductors, we can use the table in NFPA 70 Article 310.15(B)(16) for 60°C rated conductors in raceways. Based on the calculated current of 96.4 A for the original loads, we would need a minimum of 2/0 AWG copper conductors. However, based on the calculated current of 91.0 A for the new loads, we would only need a minimum of 1/0 AWG copper conductors.
Therefore, the minimum allowed gauge of the service conductors would be 1/0 AWG.
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apply 500 newtons of force until the speed reaches approximately 20 m/s. then, remove the force. describe the motion of the box
Answer:
it is at rest or you can say it is equilibriant
The box will undergo an initial period of acceleration until it reaches a speed of 20 m/s, at which point it will continue to move at a constant velocity in the absence of any external forces.
Assuming that the box is initially at rest and that there is no friction, when a force of 500 newtons is applied, the box will accelerate in the direction of the applied force. The acceleration of the box can be calculated using Newton's second law of motion:
F = m a
where F is the net force acting on the box, m is the mass of the box, and a is the acceleration of the box.
In this case, F = 500 N and m is the mass of the box, which we will assume to be 10 kg for the sake of example. Therefore, the acceleration of the box is:
[tex]a = F / m = 500 N / 10 kg = 50 m/s^2[/tex]
As the force is applied, the box will continue to accelerate until it reaches a speed of approximately 20 m/s. Once the box reaches this speed, the force is removed. Since there is no friction, the box will continue to move at a constant velocity of 20 m/s due to the principle of inertia.
In summary, the box will undergo an initial period of acceleration until it reaches a speed of 20 m/s, at which point it will continue to move at a constant velocity in the absence of any external forces.
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PART OF WRITTEN EXAMINATION:
As oxygen levels increase, polarization tends to ____
A) decrease
B) increase
C) stay the same
As oxygen levels increase, polarization tends to decrease. This is because oxygen is a highly electronegative element, meaning it has a strong attraction for electrons.
As oxygen molecules are introduced to a system, they will attract electrons away from other molecules, causing an overall decrease in polarization. This can have various effects on the system, depending on the specific context. For example, in certain chemical reactions, decreased polarization can lead to a decrease in reactivity or a decrease in the strength of intermolecular forces. However, in other contexts, such as in biological systems, decreased polarization may be beneficial, as it can help to stabilize important molecules like proteins and DNA. Overall, the relationship between oxygen levels and polarization is an important factor to consider in many different scientific fields, and can have a significant impact on the behavior of systems ranging from the smallest chemical reactions to the largest ecosystems.
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A solenoid of radius 2. 5 cm has 400 turns and a length of 20 cm. Find (a) its inductance and (b) the rate at which current must change through it to produce an emf of 75 mV
a. The inductance of the solenoid is 0.0556 H
b. The rate of change of current to produce an emf of 75 mV is -1.35 A/s.
a) The inductance of a solenoid can be calculated using the formula L = (μ₀n²πr²l) / (2l + 3r), where μ₀ is the permeability of free space, n is the number of turns per unit length, r is the radius, and l is the length of the solenoid.
Plugging in the values given, we get
L = (4π x [tex]10^{-7}[/tex] x 400² x π x 0.025² x 0.2) / (2 x 0.2 + 3 x 0.025) = 0.0556 H.
b) The emf induced in a solenoid can be calculated using the formula emf = -L(dI/dt), where L is the inductance and dI/dt is the rate of change of current.
Solving for dI/dt, we get dI/dt = -emf/L. Plugging in the values given,
we get dI/dt = -(75 x [tex]10^{-3}[/tex] V) / 0.0556 H = -1.35 A/s.
So the rate at which current must change through the solenoid to produce an emf of 75 mV is 1.35 A/s.
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The question is -
A solenoid of radius 2.5 cm has 400 turns and a length of 20 cm. Find
a) its inductance and
b) the rate at which current must change through it to produce an emf of 75 mV.
circular loop of wire 50 mm in radius carries a current of 100 a. find the (a) magnetic field strength and (b) energy density at the center of the loop.
(a) The magnetic field strength at the center of the loop is 4π × [tex]10^{-4[/tex] Tesla, and (b) The energy density at the center of the loop is 1.6 × [tex]10^3[/tex] Joules per cubic meter.
(a) To find the magnetic field strength at the center of a circular loop of wire, we can use the Biot-Savart law, which relates the magnetic field at a point to the current flowing through a nearby wire segment. For a circular loop, the magnetic field at the center is given by:
B = μ₀I/2R
where μ₀ is the permeability of free space, I is the current flowing through the loop, and R is the radius of the loop. Substituting the given values, we get:
B = (4π × [tex]10^{-7[/tex] T·m/A) × (100 A)/(2 × 0.05 m) = 4π × [tex]10^{-4[/tex] T
Therefore, the magnetic field strength at the center of the loop is 4π × [tex]10^{-4[/tex] Tesla.
(b) To find the energy density at the center of the loop, we can use the equation for magnetic energy density, which relates the magnetic field strength to the energy per unit volume of the magnetic field. The energy density is given by:
u = B²/2μ₀
Substituting the magnetic field strength we found in part (a), we get:
u = (4π × [tex]10^{-4[/tex] T)²/(2 × 4π × [tex]10^{-7[/tex] T·m/A) = 1.6 × [tex]10^3[/tex] J/m³
Therefore, the energy density at the center of the loop is 1.6 × [tex]10^3[/tex] Joules per cubic meter.
In summary, the magnetic field strength at the center of the loop is 4π × [tex]10^{-4[/tex] Tesla, and the energy density at the center of the loop is 1.6 × [tex]10^3[/tex] Joules per cubic meter. These values are important for understanding the behavior of magnetic fields and their interactions with other objects in the vicinity of the loop.
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today, this part of kansas is rolling hills and farm fields. describe the environment ni which the sediment ni this rock sample (photograph )x was deposited there about 290 million years ago.
The environment was quite different. Based on the sediment in the rock sample (photograph X), it is likely that this area was once covered by a shallow sea or ocean. The presence of fine-grained sediment, such as silt and clay, suggests that the water was relatively calm and quiet.
About 290 million years ago, during the Paleozoic era, Kansas was covered by a shallow sea known as the Permian Sea. The sedimentary rocks found in Kansas, including limestone, sandstone, and shale, were deposited in this sea over millions of years.
The environment in which sediment is deposited can provide clues about the conditions of the area at the time. Based on the type of rock you mentioned, it is likely that the sediment was deposited in a marine environment, such as a shallow sea or a shoreline. The limestone could have been formed from the accumulation of shells and other organic material from marine organisms, while the sandstone and shale could have been deposited by erosion and transport of sediment from nearby land.
In terms of the landscape, it is possible that the area that is now Kansas was a low-lying coastal plain, with rivers and streams carrying sediment into the sea. The rolling hills and farm fields seen today are a result of more recent geologic processes, such as erosion and deposition by wind and water.
Overall, the sediment in the rock sample you mentioned was likely deposited in a marine environment in what is now Kansas, during the time period of the Permian Sea.
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in a movie, tarzan evades his captors by hiding under water for many minutes while breathing through a long, thin reed. assume that the maximum pressure difference his lungs can manage and still breathe is -71 mm m m -hg h g . 1 mm m m -hg h g
Tarzan's ability to breathe through a long, thin reed while hiding under water for many minutes in the movie is quite impressive.
This technique is known as snorkeling and involves breathing through a tube while floating on the surface of the water.
The maximum pressure difference that his lungs can manage and still breathe is -71 mm Hg, which means that he can handle a drop in pressure of up to 71 millimeters of mercury below atmospheric pressure.
This is important because as he breathes through the reed, the pressure inside his lungs decreases, allowing air to flow in. However, if the pressure drops too low, his lungs will not be able to handle it and he will not be able to breathe.
Therefore, it is crucial that he does not stay under water for too long and that he is careful not to inhale too deeply. Overall, Tarzan's ability to use a reed to breathe underwater is a remarkable feat of human ingenuity and survival.
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A yo-yo is made of two uniform disks, each of mass M and radius R, which are glued to a smaller central axle of negligible mass and radius ½R. A string is wrapped tightly around the axle. The yo-yo is then released from rest and allowed to drop downwards, as the string unwinds without slipping from the central axle. Calculate the yo-yo’s linear speed and angular speed when it has descended a distance D.
To solve this problem, we can use the conservation of energy and the conservation of angular momentum.
Let's first find the gravitational potential energy at height D. The center of mass of the yo-yo drops by a distance of D/2, so the gravitational potential energy lost is:
ΔU = Mgd/2
where g is the acceleration due to gravity.
Next, we can use the conservation of energy to relate the gravitational potential energy lost to the kinetic energy gained:
ΔU = KE
1/2MV² = Mgd/2
where V is the linear speed of the yo-yo. Solving for V, we get:
V = √(gd)
Next, we can use the conservation of angular momentum to relate the initial angular momentum to the final angular momentum. Since the yo-yo starts from rest, its initial angular momentum is zero. At the bottom of the drop, the entire mass is rotating with an angular speed ω about the central axle. The moment of inertia of the yo-yo can be found by using the parallel axis theorem:
I = 2(1/2MR²) + 1/2M(1/2R)²
I = 5/4MR²
The final angular momentum is:
L = Iω
L = 5/4MR² ω
Since the string is unwinding without slipping from the central axle, the linear speed of any point on the yo-yo is related to its angular speed by:
V = ωR/2
Substituting for V, we get:
5/4MR² ω = 1/2MV²
5/4MR² ω = 1/2M(gd)
ω = (gd)/(5/2R)
Therefore, the linear speed of the yo-yo is V = √(gd), and the angular speed is ω = (gd)/(5/2R).
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80mg/dL or 0.08g/dL is equal to how many drinks?
The amount of drinks that would result in a blood alcohol concentration (BAC) of 0.08g/dL or 80mg/dL depends on various factors such as weight, gender, and the amount of time between drinks.
However, on average, it takes about 2-3 drinks for a person weighing around 150 pounds to reach a BAC of 0.08g/dL. It is important to note that different types of alcoholic beverages contain different amounts of alcohol and may affect BAC differently. Therefore, it is important to drink responsibly and always have a designated driver or plan for a safe way home. Hi! The number of drinks corresponding to a blood alcohol concentration (BAC) of 80mg/dL or 0.08g/dL varies depending on factors such as weight, gender, and the time frame in which the drinks are consumed. However, on average, a BAC of 0.08g/dL can be reached by consuming approximately 4 standard drinks within 1-2 hours for a 160-pound male or 3 standard drinks for a 120-pound female. Remember that this is just an estimate, and individual responses may vary.
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how does a galaxy influence the growth of the black hole at its centre? question 49 options: it can force matter away from the black hole, preventing the black hole from growing any larger, depending on the galaxy's spin. it provides the black hole with enough heat to form an accretion disk. it provides the black hole with matter from pre-existing interstellar gas and dust. occasionally a star could wander close enough to be torn apart and provide matter to the black hole. collisions with other galaxies could provide a lot of free matter, dust and gas pushed out of their regular orbits as a result of the collision.
The growth of a black hole at the center of a galaxy is influenced by various factors, including the availability of matter and energy.
In most cases, the black hole is fed by pre-existing interstellar gas and dust that is pulled towards it by the force of gravity. This matter forms an accretion disk around the black hole, which heats up and releases energy in the form of radiation.
Occasionally, a star may wander too close to the black hole and be torn apart by its gravitational pull. This provides additional matter to the black hole and can cause a temporary increase in its growth rate. Collisions with other galaxies can also provide a significant amount of free matter and gas that is pushed out of their regular orbits as a result of the collision.
However, the influence of the galaxy's spin can also play a role in the growth of the black hole. Depending on the orientation of the spin, it can either force matter towards the black hole or away from it, which can impact its growth rate. Overall, the complex interactions between the black hole and its host galaxy can have a significant impact on its growth and evolution over time.
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A fish in a flat-sided aquarium sees a can of fish food on the counter. To the fish's eye, the can looks to be 35 cm outside the aquarium. What is the actual distance between the can and the aquarium? (You can ignore the thin glass wall of the aquarium.)
The actual distance between the can and the aquarium is 26.3 cm.
To solve this problem, we need to use the concept of refraction. When light travels from air to water (or any other medium with a different refractive index), it bends or refracts. This means that the fish will see the can of fish food at a different angle than what it actually is outside the aquarium.
To find the actual distance between the can and the aquarium, we can use the formula:
Actual distance = apparent distance / refractive index
The refractive index of water is 1.33. So, if the fish sees the can at a distance of 35 cm, the actual distance between the can and the aquarium will be:
Actual distance = 35 cm / 1.33 = 26.3 cm
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What is the wavelength of a 256-hertz sound wave in air at STP?
A: 1.17 x 10⁶ m
B: 1.29 m
C: 0.773 m
D: 8.53 x 10⁻⁷ m
Answer:
V = 331 m/s speed of sound in dry air
λ = V / f = 331 m/s / 256 / s = 1.29 m
(B) is correct
You apply an input force of 12.5 N to the nutcracker while the output force is 50.0 N. What is the actual mechanical advantage of the nutcracker?
Answer:
The mechanical advantage (MA) of a machine is the ratio of the output force to the input force. In this case, the output force is 50.0 N and the input force is 12.5 N, so we can use the formula:
MA = output force / input force
MA = 50.0 N / 12.5 N
MA = 4
Therefore, the actual mechanical advantage of the nutcracker is 4
Rank these objects based on their mass, from largest to smallest. (Be sure to notice that the main-sequence star here has a different spectral type from the one in Part A.)
-main-sequence star of spectral type M
-the moon
-a typical black hole (formed in a supernova)
-a typical neutron star
-a one-solar-mass white dwarf
-Jupiter
Starting from the largest mass:
1. A typical black hole (formed in a supernova)
2. Main-sequence star of spectral type M
3. A typical neutron star
4. One-solar-mass white dwarf
5. Jupiter
6. The moon
Black holes are the most massive objects in the universe, with a mass that can be billions of times greater than that of our Sun. Main-sequence stars of spectral type M are still relatively massive, with a mass range of 0.1-0.5 solar masses. Neutron stars are extremely dense and have a mass range of 1.1-2 solar masses. White dwarfs, formed by the collapse of a low-mass star, have a mass range of 0.4-1.4 solar masses. Jupiter, a gas giant planet, has a mass of only 0.00095 solar masses. The moon, being a natural satellite, has a very small mass compared to the other objects listed. Ranking from largest to smallest:
1. A typical black hole (formed in a supernova): Black holes have masses several times greater than the sun. The smallest black holes, known as stellar black holes, can have a mass between 3 to 20 solar masses.
2. A one-solar-mass white dwarf: As the name suggests, a one-solar-mass white dwarf has a mass equal to that of the sun, which is approximately 1 solar mass.
3. Main-sequence star of spectral type M: M-type main-sequence stars, also known as red dwarfs, have a mass range between 0.08 to 0.45 solar masses.
4. A typical neutron star: Neutron stars are very dense, compact objects formed in the aftermath of a supernova. Their mass ranges between 1.1 to 2.3 solar masses.
5. Jupiter: Jupiter is the largest planet in our solar system, but its mass is still significantly lower than that of a star. It has a mass of about 0.001 solar masses, or 317.8 Earth masses.
6. The Moon: The Moon is the smallest object in this list, with a mass of approximately 0.0123 Earth masses or 7.34 × 10^22 kg.
So, the ranking based on mass, from largest to smallest, is: black hole, white dwarf, neutron star, main-sequence star of spectral type M, Jupiter, and the Moon.
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What length of open-closed pipe would you need to achieve the same fundamental frequency as the open-open pipe discussed in Part A?
a. Half the length of the open-open pipe
b. Twice the length of the open-open pipe
c. One-fourth the length of the open-open pipe
d. Four times the length of the open-open pipe
e. The same as the length of the open-open pipe
Answer:
E. the same as the length of the ooen open pipe
To achieve the same fundamental frequency as the open-open pipe discussed in Part A, you would need an open-closed pipe with a length that is half the length of the open-open pipe. Therefore, the correct answer is option (a) Half the length of the open-open pipe.
The fundamental frequency of an open-open pipe is determined by the formula f = v / (2 * L), where f is the frequency, v is the speed of sound, and L is the length of the pipe. In contrast, the fundamental frequency of an open-closed pipe is given by the formula f = v / (4 * L).
To achieve the same fundamental frequency for both types of pipes, you need to set their respective frequency formulas equal to each other, i.e., v / (2 * L1) = v / (4 * L2), where L1 is the length of the open-open pipe and L2 is the length of the open-closed pipe. By solving this equation, you will find that L2 = 1/2 * L1, which means that the open-closed pipe should be half the length of the open-open pipe.
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the maximum tailwind component of the airplane is 10 knots. the actual tailwind calculated is 11 knots. other aircraft are continuing to land, so you decide to ignore the limitation and land as well. which hazardous attitude are you displaying?
The hazardous attitude displayed in this situation is "invulnerability."
Invulnerability is the belief that "it can't happen to me" and can lead to a disregard for rules, procedures, and limitations.
In this situation, the pilot is ignoring a limitation on the maximum tailwind component of the airplane and landing with an actual tailwind that exceeds the limitation. This could lead to a loss of control of the aircraft during landing or other safety issues.
It's important for pilots to recognize this hazardous attitude and take steps to mitigate it, such as adhering to limitations and procedures, considering the potential consequences of their actions, and recognizing their own fallibility.
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What causes the current to flow?
A) voltage similiarties between two points
B) current similiarties between two points
C) points of equal resistance
D) resistance differences between two points
E) voltage difference between the two points
The main factor that causes the current to flow is the voltage difference between two points. When there is a difference in electrical potential between two points, the flow of electrons or charges in a circuit is initiated. The voltage difference creates an electric field that drives the charges to move from one point to another.
The other options listed, such as current similarities, points of equal resistance, and resistance differences, are important factors in understanding the behavior of the current flow, but they are not the direct cause of the current. Current similarities and points of equal resistance will result in a steady-state current flow, whereas resistance differences will result in a non-uniform current distribution. Therefore, it can be concluded that the answer to the question "What causes the current to flow?" is E) voltage difference between the two points. Understanding this fundamental concept is crucial in the study and application of electrical circuits and electronics.
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Consider the following figures. Determine the direction of the current in the current-carrying wire that produces the field indicated in the figure.
Options:
out of the screen
into the screen
toward the left
toward the right
toward the top of the screen
toward the bottom of the screen
The direction of the current in the current-carrying wire that produces the field indicated in the figure is given below.
Conventionally, a positive charge would go in the same direction as an electric current. As a result, the battery's positive terminal receives less current in the external circuit than its negative counterpart. Indeed, electrons would go in the reverse direction across the cables.
According to Fleming's right-hand rule gives which direction the current flows. The right hand is held with thumb, index finger & middle finger mutually perpendicular to each other. The thumb is pointed in direction of motion to magnetic field of conductor relative to magnetic field.
(A) from right hand rule direction of current is towards left.
(B) Out of the Screen.
(C) Lower left to upper right.
According to Fleming's Right Hand Rule, if the thumb, forefinger, and middle finger are arranged in a straight line on the right hand, the thumb will point in the direction of the conductor's motion in relation to the magnetic field, the forefinger will point in the direction of the magnetic field, and the middle finger will point in the direction of the induced current.
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Full Question ;
Consider the following figures. Determine the direction of the current in the current-carrying wire that produces the field indicated in the figure. (a) * * * * * * * * * * * Bin * O out of the screen O into the screen O toward the left toward the right toward the top of the screen toward the bottom of the screen (b) O out of the screen O into the screen O toward the left toward the right O toward the top of the screen toward the bottom of the screen (C) * * * * O out of the screen into the screen lower right to upper left lower left to upper right upper right to lower left upper left to lower right
disk a, with a mass of 2.0 kg and a radius of 50 cm , rotates clockwise about a frictionless vertical axle at 20 rev/s . disk b, also 2.0 kg but with a radius of 30 cm , rotates counterclockwise about that same axle, but at a greater height than disk a, at 20 rev/s . disk b slides down the axle until it lands on top of disk a, after which they rotate together.
Determining the angular velocity of two disks before and after a collision, the principle of conservation of angular momentum is used. The calculation involves the mass and radius of the disks, as well as their initial angular velocities. After the disks collide, they rotate together counterclockwise at an angular velocity of 50.9 rad/s.
To solve this problem, we need to use the principle of conservation of angular momentum. Before the disks collide, the angular momentum of the system is given by:
L = Ia * ωa - Ib * ωb
where Ia and Ib are the moments of inertia of disks a and b, respectively, and ωa and ωb are their angular velocities. Since the disks are rotating about a common axis, we can add their moments of inertia to get:
I = Ia + Ib
The moments of inertia of the ²are given by:
Ia = (1/2) * ma * ra²
Ib = (1/2) * mb * rb²
where ma and mb are the masses of the disks, and ra and rb are their radii.
Plugging in the values, we get:
Ia = (1/2) * 2.0 kg * (0.5 m)² = 0.5 kg m²
Ib = (1/2) * 2.0 kg * (0.3 m)² = 0.18 kg m²
I = Ia + Ib = 0.5 kg m² + 0.18 kg m² = 0.68 kg m²
Before the collision, disk a has a clockwise angular velocity of 20 rev/s, which is equivalent to:
ωa = 2π * 20 rev/s = 40π rad/s
Disk b has a counterclockwise angular velocity of 20 rev/s, which is equivalent to:
ωb = -2π * 20 rev/s = -40π rad/s
Plugging in the values, we get:
L = Ia * ωa - Ib * ωb
L = 0.5 kg m² * (40π rad/s) - 0.18 kg m² * (-40π rad/s)
L = 34.6 kg m²/s
After the collision, the two disks rotate together at the same angular velocity ω. The moment of inertia of the combined disks is:
I = Ia + Ib = 0.68 kg m²
Using the principle of conservation of angular momentum, we can set the initial angular momentum L equal to the final angular momentum I * ω:
L = I * ω
Solving for ω, we get:
ω = L / I = 34.6 kg m²/s / 0.68 kg m² = 50.9 rad/s
Therefore, the combined disks rotate counterclockwise at an angular velocity of 50.9 rad/s.
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Three point charges are located on the x-axis at the following positions: Q1 = +2. 00 μC is at x = 1. 00 m, Q2 = +3. 00 μC is at x = 0. 00, and Q3 = -5. 00 μC is at x = -1. 00 m. What is the magnitude of the electric force on Q2?
The negative sign indicates that the force is in the opposite direction to the positive direction of the x-axis (i.e., to the right).
The electric field due to Q1 at the position of Q2 is:
E1 = kQ1 / r1²
E1 = (9.0 x [tex]10^9[/tex] N·m²/C²) x (+2.00 x [tex]10^{-6}[/tex] C) / (1.00 m)²
= 1.8 x [tex]10^4[/tex] N/C (to the left)
The electric field due to Q3 at the position of Q2 is:
E3 = kQ3 / r3²
E3 = (9.0 x [tex]10^9[/tex] N·m²/C²) x (-5.00 x [tex]10^{-6}[/tex] C) / (1.00 m)²
= -4.5 x [tex]10^4[/tex] N/C (to the right)
Etotal = E1 + E3
= (1.8 x[tex]10^4[/tex] N/C) + (-4.5 x [tex]10^4[/tex]N/C)
= -2.7 x [tex]10^4[/tex]N/C (to the right)
F = QE
where Q is the charge of the particle. For Q2, we have:
F2 = Q2Etotal
= (3.00 x [tex]10^{-6}[/tex] C)(-2.7 x [tex]10^4[/tex] N/C)
= -8.1 x [tex]10^{-2}[/tex] N
The magnitude of the electric force on Q2 is therefore:
|F2| = 8.1 x [tex]10^{-2}[/tex]N
The electric field is a fundamental concept used to describe the influence that electric charges have on each other. An electric field is defined as the force per unit charge that a charged particle experiences in the presence of other charged particles. Electric fields have many applications in modern technology, including electric motors, generators, and electronic devices.
The electric field is a vector quantity, meaning that it has both magnitude and direction. The direction of the electric field is the direction in which a positive test charge would move if it were placed in the field. The electric field is created by electric charges, either by stationary charges or by moving charges. The strength of the electric field at any point in space depends on the amount and distribution of the charges creating the field. The unit of electric field is newton per coulomb (N/C) in the SI system.
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An observatory records gamma rays and radio waves from the same galaxy. Which of the following claims best indicates the signal with a longer wavelength and predicts the length of time it takes for each type of signal to get to Earth? (A) Longer Wavelength Radio waves Time Taken to Get to Earth Gamma rays take longer. (c) D Longer Wavelength Radio waves Longer Wavelength Gamma rays Longer Wavelength Gamma rays Time Taken to Get to Earth The waves take the same amount of time. Time Taken to Get to Earth Radio waves take longer. Time Taken to Get to Earth The waves take the same amount of time.
An observatory records gamma rays and radio waves from the same galaxy. The best claim that indicates the signal with a longer wavelength and predicts the length of time it takes for each type of signal to get to Earth is:
Longer Wavelength: Radio waves
Time Taken to Get to Earth: The waves take the same amount of time.
Radio waves have longer wavelengths than gamma rays, as they fall at opposite ends of the electromagnetic spectrum. However, both signals travel at the speed of light, which means they will take the same amount of time to reach Earth from the galaxy. Since they are emitted from the same source, the time taken for both types of waves to arrive at the observatory will be equal.
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The four tires of an automobile are inflated to an absolute pressure of 2.0 x 105
Pa. Each tire has an area of 0.024 m? in contact with the ground. Determine the weight (Fg) of the automobile.
The four tires of an automobile are inflated to an absolute pressure of 2.0 x 10⁵ Pa. A total of 0.024 m2 of each tire is in touch with the ground. Then the weight (Fg) of the automobile is 19.2 × 10³ N.
The definition of pressure is "force per unit area." P = F/A, for example, yields the force on a unit area. Its Pascal (Pa) SI unit is equivalent to N/m2. is a scalar quantity. its dimensions are [M¹ L⁻¹ T⁻²]. Mass times the gravitational acceleration equals weight.
Pressure is P = F/A
Force on each tire,
F' = PA = 2.0 x 10⁵ Pa × 0.024 m²
F' = 4.8 × 10³ N
For on for tires,
F = F'×4
F = 4.8 × 10³ N × 4
F = 4.8 × 10³ N × 4
F = 19.2 × 10³ N
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consider a rod of length l rotated about one of its ends instead of about its center of mass. if the mass of the rod is 5 kg, and the length is 2 meters, calculate the magnitude of the moment of inertia (i). a. 1.67 kgm^2 b. 0.833 kgm^2 c. 6.67 kgm^2 d. 3.33 kgm^2
To calculate the moment of inertia of a rod of length l rotated about one of its ends, we need to use the formula I = (1/3) * m * l^2. Here, m is the mass of the rod and l is its length.
Plugging in the values given in the question, we get:
I = (1/3) * 5 kg * (2m)^2
I = (1/3) * 5 kg * 4 m^2
I = (5/3) * 4 kgm^2
I = 6.67 kgm^2
Therefore, the correct answer is option c) 6.67 kgm^2.
It is important to note that the moment of inertia depends not only on the mass of the object but also on how the mass is distributed around the axis of rotation. In this case, since the rod is being rotated about one of its ends, the mass is not uniformly distributed and the moment of inertia is higher than if it were being rotated about its center of mass. This concept is crucial in understanding rotational motion and its applications in engineering and physics.
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The phenomenon that causes the position of the Earth's celestial poles to move among the stars called
The phenomenon that causes the position of the Earth's celestial poles to move among the stars is called precession.
Precession is a slow and gradual wobbling of the Earth's rotational axis caused by the gravitational pull of the Sun and Moon on the Earth's equatorial bulge. This means that over time, the North and South celestial poles appear to move in a circle among the stars. In addition to the precession, the Earth's axial tilt (the angle at which the Earth's North Pole is tilted relative to the plane of the ecliptic) also changes as the precession cycle goes through its 26,000-year period. This causes the position of the celestial poles to move among the stars at a rate of approximately 50 arc seconds per year.
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plsssss help me ........
Answer:
silk-ties fabric
rubber-rubber bands
cellulose-jeans
starch-food and paper
dna-genetic
Explanation:
spectra showing the light intensity of the emission from a tungsten lamp and deuterium arc lamp are shown. label which spectrum is the emission from a tungsten lamp and which spectrum is the emission from a deuterium arc lamp.
The spectrum with a continuous spectrum of colors is the emission from a tungsten lamp, and the spectrum with discrete, bright lines is the emission from a deuterium arc lamp.
The spectrum showing the light intensity of the emission from a tungsten lamp is the one with a continuous spectrum of colors, whereas the spectrum showing the light intensity of the emission from a deuterium arc lamp is the one with discrete, bright lines.
The tungsten lamp emits a continuous spectrum because it is a hot solid, and as such, it emits light across a range of wavelengths.
On the other hand, the deuterium arc lamp contains a gas that emits light only at specific wavelengths when excited by an electric current. This results in bright lines at those wavelengths, creating a distinct pattern in the spectrum.
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find the magnitude of the force that our planet's magnetic field exerts on this wire if is oriented so that the current in it is running from west to east. express your answer with the appropriate units.
The magnitude of the force that our planet's magnetic field exerts on the wire is 0.5 x 10⁻⁴ N, expressed in Newtons.
In physics, a force is an influence that causes the motion of an object with mass to change its velocity, i.e., to accelerate. It can be a push or a pull, always with magnitude and direction, making it a vector quantity.
To find the magnitude of the force that our planet's magnetic field exerts on the wire,
we can use the formula F = BIL, where F is the force, B is the magnetic field strength, I is the current, and L is the length of the wire.
The magnetic field strength of the Earth's magnetic field at its surface is approximately 0.5 Gauss or 5 x 10⁻⁵ Tesla.
Assuming the wire is 1 meter long and carrying a current of 1 ampere from west to east, we can calculate the magnitude of the force as:
F = (0.5 Gauss) x (1 ampere) x (1 meter)
F = 0.5 x 10⁻⁴ Newtons
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Bohr developed an equation for calculating the energy levels of a hydrogen atom. Which of the following can be determined using this equation? Select all that apply.
The energy needed to remove an electron completely from the hydrogen atom
The difference in energy between two energy levels in a hydrogen atom
The wavelength of a line in the atomic line spectrum for hydrogen
Bohr's equation enables us to determine the ionization energy, energy differences between energy levels, and the wavelengths associated with the atomic line spectrum for hydrogen atoms.
Bohr's equation for calculating the energy levels of a hydrogen atom provides valuable information about the atom's behavior. Using this equation, we can determine the following:
1. The energy needed to remove an electron completely from the hydrogen atom: Bohr's equation helps calculate the ionization energy, which is the amount of energy required to detach an electron from its lowest energy level (n=1) to infinity.
2. The difference in energy between two energy levels in a hydrogen atom: The equation calculates the energy levels for different orbits (n values), and by finding the difference between the energy levels, we can determine the energy gap between them.
3. The wavelength of a line in the atomic line spectrum for hydrogen: When an electron transitions between energy levels, it either absorbs or emits a photon. The energy of the photon corresponds to the difference in energy between the two levels. Using this information and the Rydberg formula, we can calculate the wavelength of the emitted or absorbed light, which corresponds to a line in the atomic line spectrum for hydrogen.
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A 1. 8-m-long, 1. 0-mm-diameter steel string is pulled by a 3. 3 × 103 n tension force. By how much is the string stretched, in mm? the young's modulus for steel is 20 × 1010 n/m2
The steel string is stretched by 0.06 mm.
We can use Hooke's Law to find the amount of stretch in the steel string:
F = kΔL
where F is the tension force, k is the spring constant (related to the Young's modulus), and ΔL is the amount of stretch.
Rearranging the equation, we get:
ΔL = F / k
The spring constant k can be expressed as:
k = A * E / L
where A is the cross-sectional area of the string, E is Young's modulus, and L is the original length of the string.
Substituting the given values, we get:
A = [tex]πr^2 = π(0.5 mm)^2 = 0.785 mm^2[/tex]
k = (π/4) * (1.0 mm)^2 * (20 × [tex]10^10 N/m^2[/tex]) / (1.8 m) = 5.50 × [tex]10^4 N/m[/tex]
Now we can find the amount of stretch:
ΔL = (3.3 × [tex]10^3 N)[/tex]/ (5.50 × [tex]10^4 N/m[/tex]) = 0.06 mm
Therefore, the steel string is stretched by 0.06 mm.
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