Lesson 1 Momentum Questions
(name)
1. Calculate the momentum of a 4.0 kg object travelling at a velocity of 12.0 m/s east.
2. A 5.0 kg object has a momentum of 25.0 kg•m/s west. What is the object’s velocity?
3. A 6.6 N object travels with a velocity of 3.0 m/s north. What is the momentum of the object?
(Express the answer in kg•m/s.)
4. A 7.0 kg object travels 2.6 m west in 1.1 s. Assuming uniform velocity, what is the momentum
of the object?
5. A 5.0 kg object drops from a height of 2.5 m above the floor. What is the object’s momentum
after 0.25 s?
6. A 26.3 kg object travels with a velocity of 21.0 m/s north. What average net force is required
to bring this object to a stop in 2.60 s?
7. An average net force of 31.6 N south accelerates a 15.0 kg object uniformly from rest to 10.0
m/s. How much time passes as the object accelerates?
8. Without finding the acceleration, calculate the average net force required to accelerate a 5.4 kg
ball from rest to 3.0 m/s east in a time of 0.75 s.
9. Without finding the acceleration, calculate the time an average net force of 225 N must act on
a 1.0 x 103 kg object to change its velocity from 2.0 m/s east to 5.0 m/s east.
10. If the mass of an object is halved and the velocity changes from left to right, the momentum
will change by a factor of
a.
b.
c.
d.
positive one-half.
negative two.
positive two.
negative one-half.
Numerical Response
1. A sports car has a maximum velocity of 160 km/h. If the car has a mass of 1230 kg, then the
maximum momentum of the car, expressed in scientific notation, is a.bc 10d kgm/s. The value
of a, b, c and d are _____, _____, _____ and _____.
(Record your three-digit answer in the numerical-response section on the answer sheet.)
Lesson 2 Impulse Questions
(name)
1. A 5.0 kg object drops from a height of 2.5 m above the floor. What is the object’s momentum
after 0.25 s?
2. An average net force of 17.0 N east acts on an object for 2.5 x 102 s. What is the impulse?
3. An average net force of 11.2 N west acts on an object, producing an impulse of 7.00 N•s west.
How long does the force act on the object?
4. A 26.3 kg object travels with a velocity of 21.0 m/s north. What average net force is required
to bring this object to a stop in 2.60 s?
5. An average net force of 31.6 N south accelerates a 15.0 kg object uniformly from rest to 10.0
m/s. How much time passes as the object accelerates?
6. An average net force of 25.0 N north acts on an object for 7.20 x 101 s. What is the change in
the object’s momentum?
7. A 5.00 kg object uniformly accelerates from rest to a velocity of 15.0 m/s east. What is the
impulse on the object?
8. An average net force causes an 11.0 kg object to accelerate uniformly from rest. If this object
travels 26.3 m west in 3.20 s, what is the change in the object’s momentum?
9. A 3.0 kg object drops from a height of 6.5 m. How far has the object fallen when its
momentum is 6.0 kg•m/s down?
10. A 1.0 kg ball hits the floor with a velocity of 2.0 m/s. If this ball bounces upward off the
floor with a velocity of 1.6 m/s, what is the ball’s change in momentum?
11. A 9.5 x 103 kg rocket is launched upward from rest by an average net force of 1.5 x 105 N
up. After 15 s, the rocket runs out of fuel. What is the velocity of the rocket once it runs out of
fuel?
12. Without finding the acceleration, calculate the average net force required to accelerate a 5.4
kg ball from rest to 3.0 m/s east in a time of 0.75 s.
13. Without finding the acceleration, calculate the time an average net force of 225 N must act
on a 1.0 x 103 kg object to change its velocity from 2.0 m/s east to 5.0 m/s east.
14. Without finding the acceleration, calculate the change in velocity of a 15 kg object when an
average net force of 95 N north acts on the object for 1.6 s.
Conservation of Momentum
1. A 30.0 kg object moving to the right at 1.00 m/s collides with a 20.0 kg object moving to the
left at m/s. If the 20.0 kg object has a velocity of 1.25 m/s to the left after the collision, what is
the velocity of the 30.0 kg object after the collision?
2. A 4.50 x 103 kg railway car travelling with a velocity of 5.0 m/s east on a level, frictionless
track collides with a stationary 6.50 x 103 kg railway car. If the two cars lock together upon
collision, what is the velocity of the combined cars following the collision?
3. A 925 kg car moving at a velocity of 18.0 m/s right collides with a stationary truck with an
unknown mass. If the two vehicles lock together upon collision and move away with a velocity
of 6.50 m/s, what is the mass of the truck?
4. A 50.0 g bullet strikes a 7.00 kg stationary wooden block. If the bullet becomes embedded in
the block, and the block with the embedded bullet moves away with a velocity of 5.00 m/s to the
right after the impact, what was the velocity of the bullet immediately before striking the block?
5. A 40.0 g object moving with a velocity of 9.00 m/s to the right collides with a 55.0 g object
moving with a velocity of 6.00 m/s to the left. If the two objects stick together after colliding,
what is their velocity after the collision?
6. A 76 kg student, standing at rest on a frictionless horizontal surface, throws a 0.20 kg object
horizontally with a velocity of 22 m/s left. What is the velocity of the student immediately after
releasing the object?
7. A 1.1 x 103 kg launcher fires a 25 kg projectile horizontally. If the projectile has a horizontal
velocity of 325 m/s east, what is the recoil velocity of the launcher?
8. A rail vehicle with a rocket engine is tested on a smooth horizontal track. Starting from rest,
the engine fires for a short period of time, releasing 4.5 x 102 kg of gases. The estimated average
velocity of the gases is 1.4 x 103 m/s to the right, while the maximum velocity of the vehicle is
45 m/s to the left. What is the mass of the rail vehicle?
9. A 7.0 kg object at rest explodes into two parts. If the first part has a mass of 2.0 kg and a
velocity of m/s right, what is the velocity of the second part?
10. A l.0 x 105 N truck moving at a velocity of 15 m/s north collides head-on with a 1.0 x 104 N
car moving at a velocity of 25 m/s south. If the vehicles stick together upon impact, what is the
velocity of the combined masses immediately after colliding?
11. A 225 g ball moves with a velocity of 30.0 cm/s to the right. This ball collides with a 125 g
ball moving with a velocity of 10.0 cm/s in the same direction. After the collision, the velocity of
the 125 g ball is 24.0 cm/s to the right.
12. What is the velocity of the 225 g ball after the collision?
Is this an elastic or inelastic collision? Provide mathematical evidence for your answer.
(Hint: Calculate the kinetic energy of the objects before and after the collision. If these energies
are not the same, the collision is classified as inelastic.)
What happened to the lost kinetic energy?
13. A 10.0 g object moving with a velocity of 20.0 cm/s to the right collides with a stationary
30.0 g object. After the collision, the 10.0 g object moves with a velocity of 6.00 cm/s to the left.
What is the velocity of the 30.0 g object after the collision?
Is this an elastic or inelastic collision? Provide mathematical evidence for your answer.
What happened to the kinetic energy that was lost?
Two-Dimensional Interactions
1. A 1.4 x 103 kg car driving with a velocity of 37.0 km/h west collides with a 2.0 x 103 kg truck
driving with a velocity of 35.0 km/h north. If these two vehicles lock together when they collide,
what is the initial velocity of the vehicles after the collision?
2. Object A has a mass of 6.2 kg and a velocity of 3.0 m/s north when it collides with object B,
which has a mass of 8.0 kg and a velocity of 3.5 m/s west. If these two masses stick together
upon colliding, what is their velocity after the collision?
3. A 4.0 x 104 N truck travelling with a velocity of 8.0 m/s west collides with a 3.0 x 104 N truck
travelling with a velocity of 5.0 m/s south. If these two vehicles lock together upon colliding,
what is the initial velocity of the vehicles after the collision?
4. A 50.0 kg object moving east at an unknown velocity collides with a 60.0 kg stationary
object. After the collision, the 50.0 kg object travelled away with a velocity of 6.0 m/s 50.0° N of
E (or 50.0°), and the 60.0 kg object travelled away with a velocity of 6.3 m/s 38° S of E (or
322°).
What was the velocity of the 50.0 kg object before the collision?
Was this an elastic or inelastic collision? Provide mathematical evidence for your answer.
What happened to the lost kinetic energy?
5. A 15.0 kg object travelling with a velocity of 7.0 m/s east collides with a 10.0 kg stationary
object. After the collision, the 15.0 kg object travels with a velocity of 4.2 m/s 20.0° S of E (or
340°).
What is the velocity of the 10.0 kg object after the collision?
Is this an elastic or inelastic collision? Provide mathematical evidence for your answer.
What happened to the lost kinetic energy?
6. An object explodes into three equal masses. One mass travels with a velocity of 15.0 m/s east.
If a second mass travels with a velocity of 10.0 m/s 45.0° S of E, what is the velocity of the third
mass?
TOPIC PRACTICE QUESTIONS 1
What is the weight of an object that has a velocity of 10.0 m/s and a momentum of 2.0 x 102
kg•m/s ?
A 1.20 x 103 kg car accelerates uniformly from rest to 25.0 m/s in 10-3 s. What is the net force
acting on the car?
Use the following information to answer the next question.
A golfer hits a 5.0 x 10 2 kg ball from a ledge, as shown in the given diagram. If the ball leaves
the face of the golf club with a horizontal velocity of 30.0 m/s, what is the impulse due to the
club?
A l.l x 103 kg car travelling at a velocity of 10.0 m/s collides head-on with a brick wall. If the car
comes to a complete rest in 0.25 s, what was the average force exerted on the car during the
collision?
If a 0.15 kg object has 9.0 J of kinetic energy, what is the magnitude of its momentum?
If Annemarie drops a 0.85 kg object from a height of 2.2 m above the floor, what will be the
object’s momentum immediately before the ball hits the floor?
A 50.0 g bullet travelling at a velocity of 375 m/s becomes embedded 25.0 cm deep in a massive
wooden block. Calculate the average force exerted on the bullet by the wood.
If a 0.50 kg object launches vertically and reaches a maximum height of 15 m, what is the
maximum momentum of the object?
Use the following information to answer the next question.
A force-time graph for a 0.75 kg object that accelerated from rest is shown. Calculate the
velocity of the object at 4.0 s. (Note: The area under the graph represents the impulse.)
Use the following information to answer the next question.
A force-time graph for a 0.50 kg object that accelerated from rest is shown. Calculate the
velocity of the object at 5.0 s.
If a 2.0 kg object accelerates horizontally from rest at a uniform rate of 3.5 m/s2, what is the
momentum of the object after 2.5 s?
If Travis throws a 0.15 kg ball at a velocity of 12 m/s vertically upward, what is the momentum
of the ball when it has travelled halfway toward its maximum height?
Use the following information to answer the next question.
A 0.020 kg pendulum bob is dropped from a height of h. If the bob has momentum of 0.070
kg•m/s at its equilibrium position, what is the value of hi
Use the following information to answer the next question.
A 0.010 kg pendulum bob is dropped from a height of h above its equilibrium position, as shown
in the given diagram. When the bob reaches its equilibrium position, the string breaks, and the
bob then acts as a projectile. After the string breaks, the bob falls 1.5 m while moving 2.0 m
horizontally.
Calculate the height (h) from which the bob was released.
A 0.45 kg ball travels with a velocity of 11.0 m/s east when it hits a wall. If the ball rebounds
with a velocity of 10.0 m/s west, what was the impulse of the wall on the ball?
A 5.0 g bullet moving with a velocity of 375 m/s hits a stationary block of wood that is 6.0 cm
thick. If the bullet emerges from the wood with a velocity of 225 m/s and the wood did not
move, what was the average force exerted on the bullet by the wood?
Munira threw a 0.15 kg ball horizontally with a velocity of 25 m/s north, while Gabriella threw a
ball of identical mass horizontally with a velocity of 22 m/s west. Calculate the sum of the
momenta of the two balls.
Use the following information to answer the next question.
A 5.0 x 102 kg roller-coaster travels from point A to point B along a frictionless track, as shown
in the given diagram.
If the momentum of the roller-coaster is zero at point A, what is its momentum at point B?
Use the following information to answer the next question.
A 98.0 N box slides 25.0 m along a 35.0° incline, as shown in the given diagram. If the force of
friction along the incline is 32.0 N and the box starts from rest at the top, what is the momentum
of the box at the bottom?
Use the following information to answer the next question.
A system containing a frictionless pulley is shown in the given diagram. The system is released,
What will be the momentum of the 2.0 kg box when the 3.0 kg box hits the floor?
What will be the momentum of the 3.0 kg box when it hits the floor?
Ilya, a 45 kg student, threw a 0.25 kg object at a velocity of 9.0 m/s east while standing on a
frictionless surface. Calculate Ilya’s velocity after he released the object.
A car moving with a velocity of 10.0 m/s east collides with a stationary truck with exactly twice
the mass of the car. If the two vehicles lock together, calculate the velocity of their combined
mass immediately after collision.
A 6.0 g ball moving with a velocity of 3.0 m/s north collides head-on with an identical ball
moving at a velocity of 2.0 m/s south, resulting in an elastic collision. Immediately after the
collision, the first ball moves with a velocity of 1.0 m/s south. What is the velocity of the second
ball after the collision?
A 5.0 g ball collides with and sticks to a second ball that is at rest. If the combined mass moves
with a velocity that is — the magnitude of the original velocity of the 5.0 g ball, what is the mass
of the 4 second ball?
A gun with an unloaded weight of 25 N, fires a 6.0 x 10-2 kg bullet at a velocity of 325 m/s west.
What is the recoil velocity of the gun?
A 40.0 kg object moving with a velocity of 2.00 m/s east collides with a 30.0 kg object moving
with a velocity of 2.00 m/s north. If the objects stick together upon collision, what is the velocity
of the combined mass immediately after the collision?
A 2.0 kg object moving with a velocity of 5.0 m/s west collides with a stationary 3.0 kg object.
After the collision, the 2.0 kg object moves with a velocity of 1.5 m/s west.
Calculate the velocity of the 3.0 kg object after the collision.
Is this an elastic or inelastic collision? Provide mathematical evidence for your answer. What
happened to the kinetic energy lost?
A 7.0 kg object moving north with an unknown velocity collides with a 5.0 kg stationary object.
After the collision, the 7.0 kg object moves with a velocity of 3.0 m/s 30.0° E of N, and the
kg object moves with a velocity of 5.0 m/s 25.0° W of N.
Calculate the velocity of the 7.0 kg object before the collision.
Is this an elastic or inelastic collision? Provide mathematical evidence for your answer. What
happened to the kinetic energy lost?
Two cars collided at an intersection. The first car had a mass of 775 kg and was travelling west.
The second car had a mass of 1 125 kg and was travelling north. Immediately after impact, the
first car had a velocity of 65.0 km/h 33.0° W of N, while the second car had a velocity of 42.0
km/h 46.0° W of N. What were the velocities of these two cars immediately before the collision?
Use the following information to answer the next question.
A 4.0 g projectile is fired at a 2.0 kg wooden pendulum, as shown in the given diagram. If the
pendulum swings to a height of 2.0 cm after the projectile becomes embedded in it, how fast was
the projectile travelling when it hit the pendulum? Explain using conservation laws.
TOPIC PRACTICE QUESTIONS 2
Which of the following properties increases when an object is lifted vertically at a constant
velocity?
Potential energy
Kinetic energy
Momentum
Mass
Momentum is conserved in
elastic collisions only
inelastic collisions only
all collisions except explosions
all collisions, including explosions
Which of the following properties may an object at rest have?
Velocity
Momentum
Kinetic energy
Potential energy
Which of the following units is used to express impulse?
kg-m2/s2
kg•m/s2
N•s
N/s
If an object has constant momentum and is infinitely distant from any source of gravitation, it
will also have
weight
impulse
kinetic energy
potential energy
In an elastic collision, which of the following properties are conserved?
Momentum and potential energy
Momentum and kinetic energy
Impulse and potential energy
Impulse and kinetic energy
7. If an object has a mass of m and a kinetic energy of EK its momentum is
a.
√
2𝐸𝐾
𝑚
b. √2EK m
c.
4𝐸𝑘 2
𝑚
d. √2𝐸𝐾
8. When the velocity of an object is tripled, which of the following quantities is also tripled?
a.
b.
c.
d.
Inertia
Momentum
Kinetic energy
Potential energy
Use the following information to answer the next question.
An object has the following quantities:
Momentum
Potential energy
Kinetic energy
When an object slides along a horizontal, frictionless surface, which of the given quantities
remains constant?
i) and ii) only
i) and iii) only
ii) and iii) only
i), ii), and iii)
The impulse experienced by an object is equivalent to its change in
velocity
momentum
kinetic energy
potential energy
Use the following information to answer the next question.
Ellen, an astronaut with a mass of 1.30 x 102 kg, including her equipment, connects a safety line
(length = 22 m) to herself and to her spacecraft (mass = 2.80 x 103 kg). (This is the initial state of
the astronaut and the spacecraft, with velocities relative to each other of 0 m/s.) Ellen then
pushes against the craft and moves away at a constant velocity of 9.00 m/s relative to her
previous null velocity.
How long will it take for Ellen’s safety line to become tight?
A. 0.418 s
B. 0.900 s
C. 2.34 s
D. 2.44 s
An uncharged subatomic particle, which has a speed of v and a mass of m, strikes the nucleus of
a large atom. Assuming that the collision is perfectly elastic and that the particle rebounds back
along the incident path, the change in the momentum of the subatomic particle is closest to
A. 0
B. mv/2
C. mv
D. 2 mv
A perfectly elastic collision conserves
momentum but not kinetic energy
kinetic energy but not momentum
both momentum and kinetic energy
neither momentum nor kinetic energy
A 0.25 kg ball hits a wall with a velocity of 3.0 m/s perpendicular to the wall. If the ball bounces
off the wall with a velocity of 2.5 m/s, also perpendicular to the wall, what was the impulse on
the ball during its contact with the wall?
0.031 N•s
0.13N•s
1.4 N•s
3.8 N•s
A 1.1 x 103 kg car travelling with a velocity of 25 km/h east collides head-on with a 2.3 x 103 kg
car travelling with a velocity of 15 km/h west. During the collision, the two cars lock together.
What is the velocity of the locked cars as they move off together immediately after collision?
1.2 km/h east
2.1 km/h west
1.8 x 101 km/h west
4.0 x 101 km/h east