Momentum Answers

Objects 1 and 2 collide and stick together. Which best describes the momentum of the resulting single object?

It is less than the momentum of object 1 but greater than the momentum of object 2.

It is greater than the momentum of object 1 but less than the momentum of object 2.

It is equal to the momentum of object 1 minus the momentum of object 2.

It is equal to the momentum of object 1 plus the momentum of object 2.

A 50 kg pitcher throws a baseball with a mass of 0.15 kg. If the ball is thrown with a positive velocity of 35 m/s and there is no net force on the system, what is the velocity of the pitcher?

−0.1 m/s

−0.2 m/s

−0.7 m/s

−1.4 m/s

A car has a momentum of 20,000 kg • m/s. What would the car’s momentum be if its velocity doubles?

10,000 kg • m/s

20,000 kg • m/s

40,000 kg • m/s

80,000 kg • m/s

What is the momentum of a 5 kg object that has a velocity of 1.2 m/s?

3.8 kg • m/s

4.2 kg • m/s

6.0 kg • m/s

6.2 kg • m/s

When someone throws a ball, the action force is the person pushing on the ball. What is the reaction force?

the ball pushing on the person

the ball pushing against air

the ball being pulled toward the ground

the ball being pulled away from the person

Denise is riding her bike and falls to the ground. During the collision, she hits both grass and cement.

The grass did not exert a reaction force.

The grass did not exert an action force.

The grass shortens the time of the collision.

The grass extends the time of the collision.

A car has a momentum of 20,000 kg • m/s. What would the car’s momentum be if its velocity doubles?

10,000 kg • m/s

20,000 kg • m/s

40,000 kg • m/s

80,000 kg • m/s

Sheila weighs 60 kg and is riding a bike. Her momentum on the bike is 340 kg • m/s. The bike hits a rock, which stops it completely and throws Sheila forward onto the pavement.If there is no net force on the system, what is Sheila’s velocity immediately after she is thrown from the bike?

1.8 m/s

2.0 m/s

5.0 m/s

5.7 m/s

The diagram shows two balls before they collide.

0.0 kg • m/s

0.2 kg • m/s

0.3 kg • m/s

0.4 kg • m/s

The chart lists the masses of four balls that have the same momentum.

The green ball has a lower velocity than the purple ball.

The red ball has a greater velocity than the purple ball.

The yellow ball has a higher velocity than the green ball.

The red ball has a greater velocity than the green ball.

Which formula can be used to express the law of conservation of momentum, where p = momentum?

pi = pf

pi > pf

pi < pf

pi ≠ pf

Football helmets are made with padding that helps reduce head injuries when a player collides with an object. Which best explains how the padding reduces injuries?

It extends the time of the collision.

It reduces the time of the collision.

It eliminates the reaction force of the object.

It eliminates the action force of the object.

Denise is riding her bike and falls to the ground. During the collision, she hits both grass and cement.

The grass did not exert a reaction force.

The grass did not exert an action force.

The grass shortens the time of the collision.

The grass extends the time of the collision.

Football helmets are made with padding that helps reduce head injuries when a player collides with an object. Which best explains how the padding reduces injuries?

It extends the time of the collision.

It reduces the time of the collision.

It eliminates the reaction force of the object.

It eliminates the action force of the object.

The chart show the masses and velocities of two colliding objects that stick together after a collision.

4,500 g · m/s

1,750 g · m/s

1,500 kg · m/s

3,000 kg · m/s

A NASA explorer spacecraft with a mass of 1,000 kg takes off in a positive direction from a stationary asteroid.If the velocity of the spacecraft is 250 m/s and the asteroid is pushed back –25 m/s, what is the mass of the asteroid? Assume there is no net force on the system.

100 kg

6,250 kg

10,000 kg

6,250,000 kg