Answers
Answer:
a = Δv/Δt = (0 - 20) / (5 - 2) = -6⅔ m/s²
Related Questions
Which car is experiencing negative acceleration?
A. a car sitting at a red light
B. a car slowing down as it approaches a red light
C. a car driving in a circle at a constant speed
D. a car changing its speed from 0 km/hr to 10 km/hr
Answers
Answer:B
Explanation:
Answer: b
Explanation: b as it slows down and decelerates
just this last one!!
A car slams on its brakes creating an acceleration of -4.7 m/s^2. It comes to rest after traveling a distance of 235 m. What was its velocity before it began to accelerate?
Answers
Answer:
[tex]47 \ \frac{m}{s}[/tex]
Explanation:
s = displacement (m)
u = initial velocity [tex](\frac{m}{s})[/tex]
v = final velocity [tex](\frac{m}{s})[/tex]
a = acceleration [tex](\frac{m}{s^{2} })[/tex]
t = time (s)
s = 235
a = -4.7
v = 0
v² = u² + 2as
(0)² = u² + 2(-4.7)(235)
u² - 2209 = 0
u² = 2209
u = 47
Answer:
[tex]\boxed {\boxed {\sf 47 \ m/s}}[/tex]
Explanation:
We are asked to find the initial velocity of the car before it began to accelerate.
We are given the acceleration, distance, and final velocity, so we will use the following kinematic equation:
[tex]{v_f}^2 = {v_i}^2 + 2ad[/tex]
The car's acceleration is -4.7 meters per second square. It traveled a distance of 235 meters. It came to rest, or a final velocity of 0 meters per second.
a= -4.7 m/s²d= 235 m [tex]v_f[/tex]= 0 m/sSubstitute the values into the formula.
[tex](0 \ m/s)^2 = {v_i}^2 + 2 (-4.7 \ m/s^2)(235 \ m)[/tex]
[tex]0 = {v_i}^2 + 2 (-4.7 \ m/s^2)(235 \ m)[/tex]
Multiply the numbers in parentheses.
[tex]0= {v_i}^2 + (-2209 \ m^2 / s^2)[/tex]
Add -2209 to both sides of the equation.
[tex]0+ 2209 \ m^2 /s^2 = {v_i}^2+ ( -2209 \ m^2 /s^2 )+ 2209 \ m^2 /s^2[/tex]
[tex]2209 \ m^2 /s^2 = {v_i}^2[/tex]
Take the square root of both sides.
[tex]\sqrt {2209 \ m^2 /s^2} = \sqrt {{v_i}^2[/tex]
[tex]\sqrt {2209 \ m^2 /s^2} = v_i[/tex]
[tex]47 \ m/s = v_i[/tex]
The inital velocity of the car was 47 meters per second.
3. A car travelling at 12 m/s into a stationary truck of about 10 times the cars mass. a. If the collision was completely inelastic, what velocity would the two travel at if the stuck together? b. If the collision was completely elastic, what would be the velocities of the car and truck after the collision? c. In order to exert a force of only 3500N on the truck during the collision, how much time would the collision have to take?
Answers
(a) The final velocity of the two vehicles if the collision was inelastic is 1.1 m/s.
(b) For the elastic collision, the final velocity of the car is 9.81 m/s backwards and the final velocity of the truck is 2.19 m/s forward.
(c) The time taken to exert the given force is 0.00625 m (s).
The given parameters;
Initial velocity of the car, u₁ = 12 m/sInitial velocity of the truck, u₂ = 0Mass of the car, = mMass of the truck, = 10m(a) The final velocity of the two vehicles if the collision was inelastic is calculated as follows;
[tex]m_1 u_1 + m_2u_2 = v(m_1+ m_2)\\\\12m + 10m(0) = v(m + 10m)\\\\12m = v(11m)\\\\v = \frac{12m}{11m} \\\\v = 1.1 \ m/s[/tex]
(b) The final velocity of the two vehicles if the collision was elastic is calculated as follows;
[tex]m_1 u_1 + m_2u_2 = m_1v_1 + m_2v_2\\\\\12m \ + \ 10m(0) = mv_1 + 10mv_2\\\\12m = m(v_1 + 10v_2)\\\\12 = v_1 + 10 v_2\ \ - --(1)[/tex]
Apply one-directional velocity equation:
[tex]u_1 +v_1 = u_2 + v_2\\\\12 + v_1 = 0 + v_2\\\\12+ v_1 = v_2 \ \ --- (2)[/tex]
Substitute the value of [tex]v_2[/tex] into equation (1);
[tex]12 = v_1 + 10(12 + v_1)\\\\12= v_1 + 120 + 10v_1\\\\12- 120 = 11v_1\\\\-108 = 11v_1\\\\v_1 = \frac{-108}{11} \\\\v_1 = -9.81 \ m/s\\\\[/tex]
Solve for [tex]v_2[/tex];
[tex]v_2 = 12 + v_1\\\\v_2 = 12 - 9.81\\\\v_2 = 2.19 \ m/s[/tex]
Thus, for the elastic collision, the final velocity of the car is 9.81 m/s backwards and the final velocity of the truck is 2.19 m/s forward.
(c)
The change in the momentum of the truck is calculated as;
[tex]\Delta P = m_2(v_2 - u_2)\\\\\Delta P = 10m(2.19)\\\\\Delta P = 21.9m[/tex]
The time taken to exert the given force is calculated as follows;
[tex]Ft = \Delta P\\\\t = \frac{\Delta P}{F} \\\\t = \frac{21.9 \ m}{3500} \\\\t = 0.00625 \ m (seconds)[/tex]
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Check if correct or not:
Directions: Using what you learned about energy describe the energy transfer or transformations for each of the items below.
1. Clapping Your Hands:
Kinetic- sound
2. Dropping Your Pencil:
3. The Toaster:
Electric-Thermal/Heat
4. A Cat Lying in a Sunny Window:
Light-Thermal/heat
5. Lifting a Book Over Your Head:
kinetic-potential
6. The Radio:
Electric-sound
Tell me if correct or not
Answers
Answer:
Looks good to me
Explanation:
#2 should probably be turning potential energy to kinetic.
Which one of the following statements concerning a collection of gas molecules at a certain temperature is true?A. The lower the temperature, the greater are the molecular speeds. B. Most of the molecules have the same kinetic energy. C. All molecules possess the same momentum. D. The molecules have a range of kinetic energies. E. All molecules move with the same velocity.
Answers
Answer:
D Is true - the velocities (and squared) follow the appropriate statistical curve
The molecules have a range of kinetic energies at a certain temperature. As the temperature increases, their kinetic energy and molecular speed increases.
What is kinetic theory of gases ?Kinetic theory of gases describes the nature of ideal gases and their volume, pressure and kinetic energy. As per this theory the gases are made of tiny particles which have negligible mass compared to that of the container.
Kinetic theory states that the kinetic energy of all gases increases with increase in temperature which is independent of the masses and and at certain temperature all the gases are having same range of kinetic energies.
The velocity of all the gaseous particles increases with increasing in temperature which results in the increase in kinetic energy. Hence, option D is correct.
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Use the periodic table to answer the question.
An illustration shows the periodic table of elements with elements arranged in increasing order of atomic number in 18 columns (groups) and 7 rows (periods).
Which comparison is correct?
(1 point)
PH3 is a stronger acid than NH3.
PH, 3, is a stronger acid than NH, 3, .
HF is a stronger acid than HCl.
HF is a stronger acid than HCl.
H2S is a stronger acid than HCl.
H, 2, S is a stronger acid than HCl.
NH3 is a stronger acid than HF.
Answers
Answer:
A: P and N are both nonmetals, same strength: No
B: Most likely not
C: Same saying as B
D: Most likely yes
Explanation:
I don't actually know if i'm right, I just want to help you okay, so if it's wrong than sorry. Also I couldn't tell if the CI is a Ci(17) or CL(6+53)
Part reason why I was saying that B and C are most likely incorrect. And D the NH3 has more value than HF (if I remember)
As per the given situation, [tex]PH_3[/tex] is stronger acid than [tex]NH_3[/tex]. The correct option is A.
What is an acid?Any substance that tastes sour in water, turns blue litmus paper red, reacts with some metals to liberate hydrogen, reacts with bases to form salts, and promotes chemical reactions is considered an acid (acid catalysis).
Because strong acids have mostly ions in solution, the bonds that hold H and A together must be weak. Strong acids easily dissociate into ions.
Because weak acids exist primarily as molecules with only a few ions in solution, the bonds that hold H and A together must be strong.
[tex]PH_3[/tex] is a more potent acid than [tex]NH_3[/tex]. as PH3 has a pKa of -5.5 and [tex]NH_3[/tex] has a pKa of 9.9.
Thus, the correct option is A.
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A body is thrown up into the air takes a time of 4s to reach the height. What is the velocity with which the body was thrown up.(g=10ms2)
Answers
Answer:
40m/s
Explanation:
V= u + at
v= 0
a= -10
t= 4
0= u -40
u= 40m/s
just trial!!!!!!!
How do I measure the drag of a paper airplane?
Answers
Answer:
hmmmmm ill get back later
Explanation:
please help
Two masses m1 and m2, are a distance R apart and mq exerts a gravitational force F on m2. What is the gravitational force is the gravitational force on M1?
Answers
Answer:
F
Explanation:
for every action there exists an equal and opposite reaction. The force acting on the two masses is identical in magnitude, but opposite in direction.
at room tmeperature none of the metals are
Answers
What metal is not at room temperature?
Mercury is a metallic chemical element that is an only metal that is not a solid at room temperature.
Four balls with different masses are dropped from the heights shown. Air resistance may be ignored. Which ball has the greatest average speed?
Answers
Answer:
The one falling from the greatest height will have the greatest speed.
h = 1/2 g t^2 time for ball to fall distance h
h2 / h1 = t2^2 / t1^2 dividing equations
h2 / t2^2 = h1 / t1^2
Let v be the average speed (v2 = h2 / t2)
1 / t2 * v2 = 1 / t1 * v1
v2 / v1 = t2 / t1 the one taking the longest to fall has the greater av. speed
Check:
h4 / h1 = t4^2 / t1^2 or
t4 / t1 = (h4 / h1)^1/2
In this case t4 / t1 = (4 / 1)^1/2 = 2 or twice the average speed
t1 = (2 h / g)^1/2 = .2^1/2 = .447 using g = 10
t4 = (2 h / g)^1/2 = .8^1/2 = .894
v1 = 1 / .447 = 2.24 m/s average speed
v4 = 4 / .894 = 4.47 or twice the average speed
What does water’s high specific heat capacity explain about water?(1 point)
why water bonds with other molecules
why water bonds with other molecules
why water is unable to absorb energy
why water is unable to absorb energy
why water is liquid at room temperature
why water is liquid at room temperature
why water is often used as a solvent
Answers
Water’s high specific heat capacity explain why water is liquid at room temperature
option C is the correct answer.
What is specific heat capacity?
The specific heat capacity of an object is the amount of heat required to raise the temperature of a unit mass of the substance by 1 kelvin.
The relationship between specific heat capacity and heat capacity of a substance is given as;
c = Q/mΔθ
where;
Q is the quantity of heat c is the specific heat capacitym is the mass of the substanceΔθ is the change in temperatureA high specific heat capacity implies that the substance absorbs more energy to change its state.
Thus, water has a high specific heat, meaning it takes more energy to increase the temperature of water compared to other substances. When water absorb more heat energy, it changes its state.
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Which sentence states Newton's second law?
Answers
Answer:
Force is equal to the change in momentum per change in time.
Explanation:
That situation is described by Newton's Second Law of Motion. According to NASA, this law states, "Force is equal to the change in momentum per change in time. For a constant mass, force equals mass times acceleration." This is written in mathematical form as Force = mass.
what is the relationship between work and mechanical advantage
Answers
Mechanical efficiency: the comparison of the machine's work output with it's work input
Mechanical advantage: the number of times that the machine multiplies the force
Explained:
what is dispersion of light?
Answers
Answer:
[tex] \huge \bold \blue{ \underline{ answer}}[/tex]
The splitting up of light into its constituent colours while passing from one medium to the other is called dispersion.
A child on ice skates is given a small push from behind by a parent. How are forces used to describe the resulting motion?(1 point)
Because of equal and opposite reactions, there will be a force opposing the push from the parent, and they will not move.
Because of equal and opposite reactions, there will be a force opposing the push from the parent, and they will not move.
There is an unbalanced force on the child, and the child’s motion will change direction or increase speed.
There is an unbalanced force on the child, and the child’s motion will change direction or increase speed.
There is a balanced force on the child, and the child’s motion will change direction or increase speed.
There is a balanced force on the child, and the child’s motion will change direction or increase speed.
Because of equal and opposite reactions, the child will move in the opposite direction to the force.
Answers
A child on ice skates is given a small push from behind by a parent. There is an unbalanced force on the child, and the child’s motion will change direction or increase speed.
A child on ice skates is given a small push from behind by a parent. How are forces used to describe the resulting motion?
Because of equal and opposite reactions, there will be a force opposing the push from the parent, and they will not move. FALSE. According to Newton's third law of motion, if the parent applies force on the child, there will be a reaction applied by the child on the parent. These forces are applied to different objects so they will not cancel and the child will move. There is an unbalanced force on the child, and the child’s motion will change direction or increase speed. TRUE. The child will have an acceleration as a consequence of the unbalanced force. The acceleration will be responsible for the change in the direction or speed of the child. There is a balanced force on the child, and the child’s motion will change direction or increase speed. FALSE. If the forces were balanced, that is, there was no net force, the movement of the child would not change, as stated by Newton's first law of motion. Because of equal and opposite reactions, the child will move in the opposite direction to the force. FALSE. The child will move in the direction of the net force.A child on ice skates is given a small push from behind by a parent. There is an unbalanced force on the child, and the child’s motion will change direction or increase speed.
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Which of the following describes the motion of a block while it is in equilibrium? The block:
A. moves at a constant speed
B. slows down gradually to stop
C. speeds up for a bit, then moves at a constant speed
D. Accelerates constantly
Answers
The statement that describes the motion of a block while it is in equilibrium is: The block moves at a constant speed.
EQUILIBRIUM:A state of equilibrium in physics refers to a state of rest or the forces exerted on the object is in a balanced state.
In dynamic equilibrium, the acceleration of a body is zero. This means that the body is moving at a uniform speed.
Therefore, the statement that describes the motion of a block while it is in equilibrium is: The block moves at a constant speed.
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why does gas have the most energy but moves the slowest
Answers
Gases have heavier molecules. Since all gases have the same average kinetic energy at the same temperature, lighter molecules move faster and heavier molecules move slower on average.
Explain why the temperature is not changing at X
Answers
Answer:
The temperature is constant at 'X'. No increase or decrease. Would be same answer if there were a 'X' at temperature 'D'.
Slope of graph is zero so no change in the temperature.
What is temperature?
Temperature is a physical quantity that expresses quantitatively the perceptions of hotness and coldness. Temperature is measured with a thermometer.
Given graph of temperature and time, at position x there in no change in temperature with time so temperature is not changing.
Slope of graph is zero so no change in the temperature.
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A simple machine where an inclined plane is wrapped in a spiral is called a lever.
Answers
Answer:
Cool. What’s the Question?
Explanation:
An object is projected with speed of 4ms at an angle of 60° to horizontal. Calculate the time of flight of the object. (g=10ms2)
Answers
0.8 seconds
Explanation:
time of flight = 2u/g
u=4m/s
g=10
= 8/10
= 0.8 sec
just a trial...not sure!!!
Given :
∅ = 60⁰
u = 4 m/s
g = 10m/s²
to find :
T = ?
Solution :
as per formula,
[tex]t = \frac{2u \: sin \theta}{g} [/tex]
now put the value : [tex]t \: = \frac{2 \times 4 \times sin \: 60}{10} [/tex]
as we know [tex] sin60 \: = \frac{ \sqrt{3} }{2} [/tex]
therefore,
[tex]t \: = \frac{8 \times \frac{ \sqrt{3} }{2} }{10} [/tex]
as we solve this we get,
[tex]t \: = \frac{ 2\sqrt{3} }{5} [/tex]
that's t = 0.69 sec
[tex]\sf\fbox\red{\:I \:hope \:it's \:helpful \:to \:you}[/tex]
A container holds 192 g of oxygen gas at a pressure of 8.00 atm.
How much heat Q is required to increase the temperature by
145 °C at constant volume?
Answers
The quantity of heat (Q) that is required to increase the temperature at constant volume is 18,082.95 Joules.
Given the following data:
Mass of oxygen gas = 192 gPressure = 8.00 atmTemperature = 145°CScientific data:
Ideal gas constant, R = 8.314 J/molKMolar mass of oxygen gas = 32 g/mol.To determine the quantity of heat (Q) that is required to increase the temperature at constant volume:
First of all, we would find the number of moles of oxygen gas.
[tex]Number\;of\;moles = \frac{mass}{molar\;mass}\\\\Number\;of\;moles = \frac{192}{32}[/tex]
Number of moles = 6 moles.
At constant volume, the heat capacity for a diatomic gas is given by:
[tex]C_v = \frac{5}{2} R\\\\C_v =\frac{5}{2} \times 8.314[/tex]
Heat capacity = 20.785 J/molK.
At constant volume, the quantity of heat (Q) is given by this formula:
[tex]Q = nC_v \Delta T\\\\Q=6 \times 20.785 \times 145[/tex]
Quantity of heat (Q) = 18,082.95 Joules
Note: [tex]\Delta T[/tex] = 145°C = 145 K (since the difference is the same).
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A volleyball that has an initial momentum of
−
1.0
kg
⋅
m
s
−1.0kg⋅
s
m
minus, 1, point, 0, start text, k, g, end text, dot, start fraction, start text, m, end text, divided by, start text, s, end text, end fraction changes direction after a hand hits it with a force of
150
N
150N150, start text, N, end text for
0.01
seconds
0.01seconds0, point, 01, start text, s, e, c, o, n, d, s, end text.
A hand hits a volleyball. An arrow points to the right, in the directio
Answers
Answer:
10-
Step-by-Step Explanation:
Michelle recently started selling her invention: A bed that looks like it floats in mid-air. The bed is actually suspended by magnetic forces. Michelle is a(n)
Answers
Answer:
Explanation:
designer
illusionist
engineer
entrepreneur
salesperson
human
inventor
Observe and compare the forces acting on the turtle and the cat.
a turtle and a cat on the ground looking at each other and not moving
Public Domain
The forces are balanced on both animals because they are not moving.
The forces are unbalanced on both animals because they are not moving.
The forces are balanced on the turtle but unbalanced on the cat because it is heavier.
The forces are balanced on the cat but unbalanced on the turtle because the cat is larger.
Answers
Answer:
The forces are balanced on both animals because they are not moving
More importantly than not moving is not accelerating.
Explanation:
Answer: A! the animals are doing the same thing, the force is applied to both also there not moving
Explanation:
A student removed a wool hat from her head. Her hair stood up from static electricity. What did her hat do to cause this
Answers
Answer:
A student removed a wool hat from her head. Her hair stood up from static electricity. What did her hat do to cause this? ... Yes, the motor would run faster because the increased electrical force increases the magnetic force in the motor.
A student removed the wool from her head due to the static charge of electricity, it is caused.
What is charge?A difference in electric charge within, on the surface of, or between two materials results in static electricity. Until it can be expelled through an electrical discharge or current, the charge stays. In contrast to current electricity, which transmits energy by letting an electric charge flow through a conductor or a space, static electricity does not transport energy.
When two surfaces come into contact, wear, and separate from one another when at least a single surfaces has a good resistance to electric current, a static electrostatic attraction can be produced. Because individuals can feel, hear, and even see a spark when the extra charge is neutralized when placed close to a powerful electrical conductor, most people are familiar with static electricity's effects.
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Section 1: Basic Energy Relationships
1. Click/tap the Start button and observe the motion. View the bar
charts and the velocity value as the coaster car moves. Complete
the following paragraph by entering total mechanical energy
(ME), kinetic energy (KE), and potential energy (PE). The
labeled locations refer to the graphic at the right.
As the coaster car rolls down the track from A to E, the
________ values decrease and the _______ value
increase and the ________ values remain constant. The
_______ is greatest at point A and smallest at point E.
However, the _______ is smallest at point A and largest
at point E.
Section 2: Hill Design
2. Click/tap on the Bumps tab at the top of the
Interactive. Then drag the grey circles to modify the
track so that it looks like the track design at the right.
Pay attention to the background grid to help with the
design. Note that Dot G is at the same height as Dot E;
make sure that the same is true of your final design.
3. Run the simulation. Does the coaster car travel as high
as point H? ___________ Give an explanation for why
it does or doesn't reach point H.
Answers
As the coaster car rolls down the track from A to E, the potential energy values decrease and the kinetic energy value increase and the total mechanical energy values remain constant. The potential energy is greatest at point A and smallest at point E. However, the kinetic energy is smallest at point A and largest at point E.
According the principle of conservation of mechanical energy, as the potential energy decreases, the kinetic energy increases.
[tex]P.E + K.E = M.A[/tex]
At point A, the coater has maximum potential energy.
At point E, the coaster has maximum kinetic energy.
We can fill the blanks as follows;
As the coaster car rolls down the track from A to E, the potential energy values decrease and the kinetic energy value increase and the total mechanical energy values remain constant. The potential energy is greatest at point A and smallest at point E. However, the kinetic energy is smallest at point A and largest at point E.
Based on the principle of conservation of mechanical energy, if the second simulation occurs at the same condition as the first, the height reached by coaster will be same.
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The vertical and horizontal components of the velocity of a golf ball after being struck by a club are 4.0 m s1 and 5.0 m s respectively. Determine the magnitude and direction of the velocity of the golf ball. A 6.30 m s-1 B 6.35 m s-1 C 6.40 m s-1 D 6.45 m 5-1
Answers
The magnitude and direction of the velocity of the golf ball is 6.4 m/s at 38.7⁰.
The given parameters:
Vertical component of the velocity, [tex]v_y = 4 \ m/s[/tex]Horizontal component of the velocity, [tex]v_x = 5 \ m/s[/tex]The magnitude of the resultant velocity of the golf ball is calculated as follows;
[tex]v= \sqrt{v_y^2 + v_x^2} \\\\v = \sqrt{4^2 + 5^2} \\\\v = 6.4 \ m/s[/tex]
The direction of the golf ball's velocity is calculated as follows;
[tex]\theta = tan^{-1} (\frac{v_y}{v_x} )\\\\\theta = tan^{-1}(\frac{4}{5} )\\\\\theta = 38.7 \ ^0[/tex]
Thus, the magnitude and direction of the velocity of the golf ball is 6.4 m/s at 38.7⁰.
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A volcano launches a lava bomb straight upward with an initial speed of 24 m/s. speed at 2 and 3 seconds and it it is upward or downward
Answers
Answer:
Explanation:
v = u + at
Let Up be the positive direction
v(2) = 24 + (-9.8)(2) = 4.4 m/s Positive result means Upward
v(3) = 24 + (-9.8)(3) = -5.4 m/s Negative result means Downward
which one would cool down faster, water or a block of concrete? why?
Answers
Answer:
If you mean by temperature
Water, cause say the water just sits there, it'll take a few minutes to cool down. But for concrete having all the hot sun rays on it during summer, can make it very hot, if you put 'cold water' there, it'll only last there for a moments (and that's by effect not waiting), if you wait for it to cooldown by itself, it'll take quite awhile.
If you mean solidify:
The stuff required to make concretes takes HOURS and HOURS to finish solidifying, unlike water being turn into ice normally only takes about half an hour or an hour (maybe 2) in the freezer (I don't know how long for ice, but not long at all in comparison to concrete).
Explanation:
Explanation was mostly part of the answer