Answer:
Explanation:
F = ma
a = F/m = 21/3 = 7 m/s²
A circular disk of radius 0.200 m rotates at a constant angular speed of 2.50 rev/s. What is the centripetal acceleration (in m/s2) of a point on the edge of the disk?
[tex]a_c = 3.14\:\text{m/s}^2[/tex]
Explanation:
First, we need to convert the given angular speed [tex]\omega[/tex] from rev/s to rad/s:
[tex]2.50\:\dfrac{\text{rev}}{\text{s}}×\dfrac{2\pi\:\text{rad}}{1\:\text{rev}} = 15.7\:\text{rad/s}[/tex]
The centripetal acceleration [tex]a_c[/tex] is defined as
[tex]a_c = \dfrac{v^2}{r}[/tex]
Recall that [tex]v = r\omega[/tex] so we can write [tex]a_c[/tex] as
[tex]a_c = \dfrac{(r\omega)^2}{r} = \omega^2r[/tex]
[tex]\;\;\;\;\;=(15.7\:\text{rad/s})^2(0.200\:\text{m}) = 3.14\:\text{m/s}^2[/tex]
A car starting from rest has a constant acceleration of 5 m/s2. How long will it take to reach a speed of 20 m/s
Answer:
Explanation:
v = u + at
20 = 0 + 5t
t = 20/5
t = 4 s
Compare the time it
takes the light to travel from your
teacher to your eye with the time
it takes sound to travel the same
distance.
Answer:
Light takes less time than sound.
Explanation:
Let's say, the teacher and the student are at a distance "d" from each other.
The medium around them would be air.
And,
The speed of light in air is approx. 3× 10⁸ m/s
while, the speed of sound in air is approx. 330 m/s
We have a formula that establishes the relation between speed, distance and time.
[tex] \boxed{ \mathsf{speed = \frac{distance}{time} }}[/tex]
Our hunt for time — Speed in both the scenarios is known to us whereas the distance is same.
Sound
[tex] \mathsf{330 = \frac{d}{time_{s}} }[/tex]
[tex] \underline{\mathsf{time _{s} = \frac{d}{330} }}[/tex]
Light
[tex] \mathsf{3 \times {10}^{8} = \frac{d}{time _{l} } }[/tex]
[tex] \underline{ \mathsf{ time _{l} = \frac{d}{3 \times {10}^{8}} }}[/tex]
The best way of comparison is finding their ratio.
[tex] \implies \mathsf{\frac{ time_{s}}{time_{l} } = \frac{ \frac{d}{330} }{ \frac{d}{3 \times {10}^{8} } } }[/tex]
simplifying the fraction
[tex] \implies \mathsf{\frac{ time_{s}}{time_{l} } = \frac{d \times (3 \times {10}^{8} )}{330 \times d}}[/tex]
d gets canceled and we're left with the following expression
[tex] \implies \mathsf{\frac{ time_{s}}{time_{l} } = \frac{ (3 \times10 \times {10}^{7} )}{330}}[/tex]
30, being a common factor in the numerator as well as denominator, gets canceled out. and in its place remains 1/ 11
(why?
=> 30÷330 = 1÷11)
[tex] \implies \mathsf{\frac{ time_{s}}{time_{l} } = \frac{ 1\times {10}^{7} }{11}}[/tex]
taking timeₛ to the numerator on the other side.
[tex] \implies \mathsf{time_{s} = \frac{ 1\times {10}^{7} }{11}\times time_{l}}[/tex]
Therefore, we get timeₛ is approx. 10⁶ times the timeₗ.
That's a big difference, no wonder light's way much faster than sound.
As lesser the time taken to cover a distance, faster is the wave.
The sound takes about 874,000 times MORE time than the light takes.
Are these a Chemical or Physical Change??
1. Sodium Bicarbonate breaks down into sodium carbonate and water.
A. Chemical Change
B. Physical Change
2. Mercury is cooled until it is in the solid state.
A. Chemical Change
B. Physical Change
The change of sodium bicarbonate breaking down into sodium carbonate and water is a chemical change. The cooling of mercury until it is in the solid state is physical change. The correct option for 1 is A and for 2 is B.
What is chemical and physical change?A chemical change occurs as a consequence of a reaction, whereas a physical change occurs when transformation occurs forms but retains its chemical identity.
Chemical changes include burning, cooking, rusting, and rotting. Physical changes include boiling, melting, freezing, and shredding.
A physical change is required to a specimen of matter in which some of the material's properties change but the matter's identity does not.
Physical changes can be classified as either reversible or irreversible. Melting is a reversible physical change because the melted ice cube can be refrozen.
In the first case, sodium bicarbonate is breaking down and forming sodium carbonate and water, this implies a chemical change.
In the second case, mercury is just cooling down, changing its physical shape. So it is physical change.
Thus, the correct option for 1 is A and for 2 is B.
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You are investigating how objects move when they are dropped from different heights. To collect your data, you drop a 1 kg weight from different heights and record the time it takes for the object to hit the ground when dropped from different heights. The data you collect is shown below:
Height dropped (m)
Time to fall (s)
1.0
0.45
2.0
0.63
3.0
0.78
4.0
0.89
Next, you plan to drop a 5 kg weight from the same heights. How will your time values in your new data table for the 5 kg weight compare to the time values in the old data table for the 1 kg weight?
The time of motion of the 5 kg object will be the same as 1 kg since both objects are dropped from the same height.
The given parameters;
Mass of the first object, m1 = 1 kg
Mass of the second object, m2 = 5 kg
The final velocity of the objects during the downward motion is calculated as follows;
[tex]v_f = v_0 + gt\\\\v_f = 0 + gt\\\\\v_f = gt[/tex]
The time of motion of the object from the given height is calculated as;
[tex]h = v_0 t + \frac{1}{2} gt^2\\\\h = 0 + \frac{1}{2} gt^2\\\\h = \frac{1}{2} gt^2\\\\gt^2 = 2h\\\\t^2 = \frac{2h}{g} \\\\t = \sqrt{\frac{2h}{g} }[/tex]
The time of motion of each object is independent of mass of the object.
Thus, the time of motion of the 5 kg object will be the same as 1 kg since both objects are dropped from the same height.
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Anyone know? plzz It's a grade.
Answer:
Gregor Mendal discovered the basic laws of inheritance he concluded that genes come in pairs and are are inherited from each parent. Rosalind Franklin discovered the structure of DNA(Deoxyribonucleic Acid), and RNA(Ribonucleic Acid). She also discovered about the double helix structure of DNA. She works on the composition of the human body and her discoveries were vast. Watson and Clark were one of the greatest genetic discoverers ever. They were the ones who rose modern molecular biology. In short terms, they were the ones concerned with how genes work and there role in DNA Replication.
Explanation:
True or False If the mass of the object increases, then the potential energy of the object decreases.
Answer:
The amount of gravitational potential energy an object has depends on its height and mass. The heavier the object and the higher it is above the ground, the more gravitational potential energy it holds. Gravitational potential energy increases as weight and height increases.
Explanation:
Answer:
Explanation:
It depends on where your reference frame for potential energy is chosen.
If a mass is above the reference origin and mass increases, potential energy will increase so the statement is FALSE
If the mass is at the reference origin and the mass increases, the potential energy stays constant at zero so the statement is FALSE
If the mass is below the reference origin and the mass increases, then the potential energy goes from a negative value to an even lower negative value so the statement in this case is TRUE
A 70 kg hunter, standing on frictionless ice, shoots a 42 g bullet horizontally at a speed of 650 m/s . Part A What is the recoil speed of the hunter
Answer:
Explanation:
momentum is conserved. Initial momentum was zero, so final total momentum must also be zero
0.042(650) + 70v = 0
v = -0.39 m/s
|v| = 0.39 m/s
Why is acceleration of an object moving at a constant velocity always zero?
Answer:
If an object is moving with a constant velocity, then by definition it has zero acceleration. So there is no net force acting on the object. The total work done on the object is thus 0 (that's not to say that there isn't work done by individual forces on the object, but the sum is 0 ).
Explanation:
In the middle, when the object was changing position at a constant velocity, the acceleration was 0. This is because the object is no longer changing its velocity and is moving at a constant rate.
a heavy jar sits on top of a 3.4 m shelf with a gravitational potential energy of 180 j. What is the mass of the jar?
Answer:
5.2941176471 kg or 5294.1 grams
Explanation:
g.p.e= mgh
g.p.e/gh=m
180j/10×3.4= m
180/34= m
5.2941 kg= m
2. An object is falling under gravity with terminal velocity. What is happening to its speed?
A. It is decreasing to a lower value.
B. It is increasing
C. It is decreasing to zero.
D. It is staying constant.
Answer:
the speed of the object has become constant.
Explanation:
At terminal velocity, air resistance equals in magnitude the weight of the falling object. Because the two are oppositely directed forces, the total force on the object is zero, and the speed of the object has become constant.
a stone is thrown down off a bridge with a velocity of 22 m/s. what is its velocity after 1.5 seconds has passed?
Answer:
Velocity of the stone after 1.5 seconds has passed = 37 m/s
Explanation:
Initial velocity (u) = 22 m/s
Time (t) = 1.5 sec
Acceleration due to gravity (g) = 10 m/s²
By using kinematics equation:
v = u + gt
v = 22 + 10 × 1.5
v = 22 + 15
v = 37 m/s
Final velocity (v) = 37 m/s
What is Acceleration?
Answer:
Depends on what are you looking at. All of the following are valid definitions, it just depends on which way you are analizing the problem.
From a kinematics point of view:
Acceleration is, by definition, is a vector quantity that measures the rate of change of the rate of change in position (add brackets if it helps visualizing the idea). This leads to the following different definitions - which are more like means of calculating it
the second derivative of position with respect to time [tex]a = \ddot x= \frac{d}{dt}({\frac d{dt}} x)[/tex];the first derivative of velocity with respect to time [tex]a = \dot v = \frac d{dt} v[/tex].From a dinamics point of view
Acceleration is the effect of a force applied to a body, and measures the ratio of the force applied to a body of mass m and the mass itself (which is another formulation of Newton second law):
[tex]a = \frac Fm[/tex]
Acceleration is the rate of change of velocity
To define acceleration, We need to know more about motion.
Motion: This can be defined as the change in position of a body from one point to another. When an object accelerates, it undergoes motion.
Definition
Acceleration can be defined as the rate of change of velocity. The S.I unit of acceleration is meter-per-squared seconds. (m/s²)
The formula of acceleration is
a = (v-u)/t................. Equation 1⇒ Where:
a = accelerationu = initial velocityv = final velocityt = timeHence, Acceleration is the rate of change of velocity
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In order to create a charged object, you need to ________.
A 0.75 kg model car is moving west at a speed of 9.0 m/s when it collides head-on with a 2.00 kg model truck that is traveling east at a speed of 10.0 m/s. After the collision, the 0.75 kg model car is now moving east at 11 m/s. What is the speed and direction of the model truck after the collision?
Answer:
2.5 m/s east
Explanation:
Let east be the positive direction for velocity.
The change in momentum of the 0.75 kg model car is ...
m1·v2 -m1·v1 = (0.75 kg)(11 m/s) -(0.75 kg)(-9 m/s)
= (0.75 kg)(20 m/s) = 15 kg·m/s
The change in momentum of the 2.0 kg model car is the opposite of this, so the total change in momentum is zero.
m2·v2 -m2·v1 = (2 kg)(v2 m/s) -(2 kg)(10 m/s) = 2(v2 -10) kg·m/s
The required relation is ...
15 kg·m/s = -2(v2 -10) kg·m/s
-7.5 = v2 -10 . . . . divide by -2
2.5 = v2 . . . . . . . add 10
The velocity of the model truck after the collision is 2.5 m/s east.
PLSSS HELP WILL MARK AS BRIANLIEST
The atomic mass is equal to the number of ______.
A.Protons
B.Electrons and neutrons
C.Neutrons and protons
D.neutrons
Which of the following waves DO NOT require a medium to travel?
Answer:
hey man, think you forgot to put the questions
Tony brought 9 2/3pitchers of juice to a volleyball game, and the players drank3 7/8pitchers of it. How much juice is left?
Rewrite the amounts as improper fractions:
9 2/3 = 29/3
3 7/8 = 31/8
Rewrite both fractions with a common denominator
29/3 = 232/24
31/8 = 93/24
Now subtract: 232/24 - 93/24 = 139/24
Rewrite as a proper fraction: 5 19/24
Answer 5 19/24
The equation below can be used to calculate a change in gravitational potential energy. What units must be used for h? Give the full name, not the abbreviation.
e=m x g x h
Answer:
h = change in vertical position (height)
has units of distance.
Explanation:
The equation below can be used to calculate a change in gravitational potential energy then the units used for the height would be meters.
What is mechanical energy?
The sum of all the energy in motion (total kinetic energy) and all the energy that is stored in the system (total potential energy) is known as mechanical energy.
As given in the problem, the equation below can be used to calculate a change in gravitational potential energy, the units used for the height of the object would be in meters, which is the SI unit of the length
The gravitational potential energy = mass×acceleration ×height
Thus, the unit of height used in the gravitational potential energy formula would be meter.
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Challenge
Marks: 1
How much energy is transferred by a 500 watt heater that is on for 2
minutes?
Answer:
Explanation:
500 W = 500 J/s
500 J/s(2 min(60 s/min) = 60000 J
4 points
This machine has a sharp edge and helps spread or cut something
all pressure topics in physics
Use the circuit diagram to decide if the lightbulb will
light. Justify your answer.
Answer:
The light bulb will NOT light because the lower switch being closed makes a short circuit. The light will have a high resistance and the electricity will choose to flow the easiest way possible through the low resistance wires.
Explanation:
Which statement about diffraction is correct?
A. Sound waves bend around the corners of various obstacles.
B. Sound waves can only travel in straight lines.
C. The amplitudes of two waves combine to appear as a wave smaller than the individual waves.
D. The amplitudes of two waves combine to appear as one big wave.
Answer:
I think A
Explanation:
Which statement about diffraction is correct?
A. Sound waves bend around the corners of various obstacles.
B. Sound waves can only travel in straight lines.
C. The amplitudes of two waves combine to appear as a wave smaller than the individual waves.
D. The amplitudes of two waves combine to appear as one big wave.
If you are good at activities that require agility, what are you able to do well?
1.maintain your heart rate in the upper ranges
2.quickly change the direction of your movement
3.hold a difficult position for a long period of time
4.strategize about the best way to win a game
Answer:
2.quickly change the direction of your movement
Explanation:
Telescopes work by using optics with true or false
Answer: true
its making me add 20 word so here they are g g g g g g g gg g t
Answer: its FALSE
Explanation:
Telescopes work by using optics with light is false, just took the quiz.
A ball is launched from ground level at 30 m/s at an angle of 35° above the horizontal. how far does it go before it is at ground level again
Answer:
Explanation:
Ignoring air resistance
Initial vertical velocity is 30sin35 = 17.2 m/s
Gravity reduces this velocity to zero in a time of
t = v/g =17.2 / 9.8 = 1.755 s
it takes the same time to come back down to ground level for a total flight time of 2(1.755) = 3.51 s
The horizontal velocity is 30cos35 = 24.57 m/s
the distance traveled horizontally is
d = vt = 24.57(3.51) = 86.298... = 86 m
(0.50kg)(6.0mls)+(1.00kg)(-12.00mls)
Answer:
-9.0 × 10-6 m3 kg
Explanation:
I'm not sure if that's what you're looking for nor do I know how to explain it.
A .223 rifle bullet, traveling at 370.m/s, hits a block of pine wood, and goes in, to a depth of 0.130m. The mass of the bullet is 1.75g (mass = 0.00175kg). Assume a constant slowing force. (A) What is the acceleration that the bullet experiences as it comes to a stop? (B) How much time is required for the bullet to stop? (C) What force, in Newtons, does the wood exert on the bullet?
Answer:
Explanation:
A)
v² = u² + 2as
a = (v² - u²) / 2s
a = (0² - 370²) / (2(0.130))
a = -526,538 m/s²
B)
t = v/a
t = 370 / 526538
t = 0.0007027... s or 0.7 ms
C)
F = ma
F = 0.00175(526,538) = 921.442307... = 921 N
Find the required angular speed, ω, of an ultracentrifuge for the radial acceleration of a point 1.60 cm from the axis to equal 300000 g (where g is the acceleration due to gravity).
Express your answer numerically in revolutions per minute.
Answer:
Explanation:
300000(9.8) = ω²(0.0160)
ω = 13555 rad/s
13555 rad/s (60 s/min/ 2π rad/rev) = 129,445 rev/min