Pre AP PhysicsMomentum and Impulse WS

  1. A compact car, mass 725 kg, is moving at +100 km/h. What is its momentum? [20139.05 kg m/s]
  2. A snowmobile has a mass of 2.5 x 102 kg. It is acted upon by a force so that its velocity changes from 6.0 m/s to 28 m/s. What is the change in its momentum? [5500 kg m/s]
  3. Jenny has a mass of 35.6 kg and her skateboard has a mass of 1.3 kg. What is the momentum of Jenny and her skateboard together if they are going 9.50 m/s? [350.55 kg m/s]
  4. A 0.20 kg baseball is pitched horizontally with a speed of +40 m/s. When it hits the bat a force of 1.7 x 104 N acts on the ball to send it soaring in the opposite direction. If the bat and ball are in contact for 8.0 x 10-3 s, what is the impulse delivered to the ball by the bat? [136 N s]
  5. A hockey player makes a slap shot, exerting a force of 30.0 N on the puck for 0.16 s. What impulse is given to the puck? [4.8 N s]
  6. A basketball of mass 0.23 kg is thrown horizontally against a rigid vertical wall with a velocity of 20 m/s. It rebounds with a velocity of 15 m/s. a) Calculate the impulse of the force of the wall on the basketball.

[-8.05 N s]

b) What is the force of the wall on the basketball if it remains in contact with the wall for 0.5 s? [-16.1 N]

  1. A 125 g snowball is traveling with a speed of 22 m/s when it hits the fence. If the snowball is completely stopped by the fence and does not rebound, what is the impulse of the force of the fence on the snowball? [-2.75 N s]
  2. A woman of mass 50 kg is swimming with a velocity of 1.6 m/s. If she stops stroking and glides to a stop in the water, what is the impulse of the force that stops her? [-80 N s]
  3. A 0.41 kg football that is initially at rest acquires a velocity of 35 m/s when it is kicked. If the kicker’s boot remains in contact with the ball for 0.08 s, what is the average force of the kick? [179.375 N]
  4. A 1.5 kg object moving with a speed of 2.5 m/s strikes a wall and the ball rebounds with a speed of 1.5 m/s. The ball is in contact with the wall for 0.045 s. What is the magnitude of the average force exerted on the ball by the wall? [-133.333 N]
  5. A 1525 kg car traveling 30 m/s crashes into a concrete wall. The front of the car crumples and the car comes to rest in 0.12 s. Calculate the average force exerted on the car by the wall. [-381250 N]
  6. A woman, driving a golf ball off of the tee, gives the ball a speed of 20.0 m/s. The mass of the ball is 45 g and the duration of the impact with the golf club is 6.0 x 10-3 s. a) What is the change in the momentum of the ball? [0.9 kg m/s]

b) Determine the average force applied by the club. [150 N]

  1. A 0.144 kg baseball is pitched horizontally at +38 m/s. After it is hit by a bat, it moves horizontally at -38 m/s. a) What impulse did the bat deliver to the ball? [-10.944 kg m/s]

b) If the bat and ball were in contact 8.0 x 10-4 s, what was the average force the bat exerted on the ball?

[-13680 N]

c) Find the acceleration of the ball during its contact with the bat. [-95000 m/s2]

  1. A 32 g bullet strikes a 5 kg block of wood that is initially at rest and embeds in the wood. If the subsequent velocity of the block is 3.8 m/s, calculate the initial velocity of the bullet. [597.55 m/s]
  2. A 0.105 kg hockey puck moving at 48 m/s is caught by a 75 kg goalie at rest. With what speed does the goalie slide on the ice? [0.0671 m/s]
  3. A 35.0 g bullet moving at 475 m/s strikes a 2.5 kg wooden block. The bullet passes through the block, leaving at 275 m/s. The block was at rest when it was hit. How fast is it moving when the bullet leaves? [2.8 m/s]
  4. A 0.5 kg ball traveling at 6.0 m/s collides head on with a 1.00 kg ball moving in the opposite direction at a velocity of -12.0 m/s. The 0.50 kg ball moves away at -14.0 m/s after the collision. Find the velocity of the second ball. [-2.0 m/s]
  5. A 95 kg fullback, running at 8.2 m/s collides in midair with a 128 kg defensive tackle moving in the opposite direction. Both players end up with zero speed. a) What was the fullback’s momentum before the collision? [779 kg m/s]

b) What was the change in the fullback’s momentum? [-779 kg m/s]

c) What was the tackle’s original momentum? [-779 kg m/s]

d) What was the change in the tackle’s momentum? [779 kg m/s]

  1. Two 75 kg campers are in the middle of a creek in a 45 kg boat without a paddle. All they have on board the boat is a quantity of 0.50 kg cans of beans. One of the campers is able to throw a can with a speed of 26.8 m/s. How many cans of beans must the camper throw to give the boat a speed of 1.0 m/s? Ignore friction. Since mass of cans is so much less than the mass of the boat initially, can ignore mass of cans initially as well. [15 cans]

Extra Practice

1. In order to catch a ball, a baseball player moves his or her hand backward in the direction of the ball's motion. Doing this reduces the force of impact on the player's hand principally because ______.

A) the velocity of the hand is reduced.B) the time of impact is decreased.

C) the momentum of impact is reduced.D) the time of impact is increased.

E) none of the above

2. Two gliders having the same mass and speeds move toward each other on an air track and stick together. After the collision the velocity of the gliders is ______.

A) twice the original velocity.B) There is not enough information to say.

C) one half the original velocity.D) zero.

E) the same as the original velocity.

3. A piece of putty moving with 1 unit of momentum strikes and sticks to a heavy bowling ball that is initially at rest. After the putty sticks to the ball, both are set in motion with a combined momentum that is ______.

A) Not enough information to sayB) more than 1 unit.

C) 1 unit.D) less than 1 unit.

4. A 4-kg ball is thrown at 8 m/s. What is the ball's momentum? [32 kg m/s]

5. A 10-kg ball has a momentum of 55 kg m/s. What is the ball's velocity? [5.5 m/s]

6. A ball is moving at 8 m/s and has a momentum of 56 kg m/s. What is the ball's mass? [7 kg]

7. True/ False When two objects collide and completely bounce apart with no lasting deformation or generation of

heat, the collision is said to be elastic.

8. True/False When two objects collide and completely stick together, the collision is said to be inelastic.

9. True/False Automobile dashboards that are padded lengthen the time of impact in case of a collision.

10. A 5.0-kg blob of clay moving horizontally at 2.0 m/s has a head-on collision with a 6.0-kg blob of clay that moves

toward it at 1.0 m/s. What is the speed if the two blobs stuck together immediately after the collision? [0.364 m/s]

11. A 0.215-kg hockey puck moving at 53 m/s is caught by a 70-kg goalie at rest. With what velocity does the goalie slide on the ice after catching the puck? [0.162 m/s]

12. A 0.044 kg bullet strikes a 6.0-kg stationary wooden block and embeds itself in the block. The block and bullet move together at 9.7 m/s. What was the original velocity of the bullet? [1332.427 m/s]

13. A 48 g bullet moving at 500 m/s strikes a 3.2 kg wooden block. The bullet passes through the block, leaving at 225 m/s. The block was at rest when it was hit. How fast is it moving when the bullet leaves? [4.125 m/s]

14. A 0.75-kg ball traveling at 7.3 m/s rightward collides head-on with a 1.15-kg ball moving in the opposite direction at a velocity of 13.0 m/s. The 0.75-kg ball moves away at 16 m/s leftward after the collision. Find the velocity of the second ball. [2.196 m/s]

15. A 3500-kg truck moving rightward with a speed of 7 km/hr collides head-on with a 1200-kg car moving leftward with a speed of 11 km/hr. The two vehicles stick together and move with the same velocity after the collision. Determine the post-collision velocity of the car and truck. [0.668 m/s]

16. During a goal-line stand, a 80-kg fullback moving eastward with a speed of 8.6 m/s collides head-on with a 110-kg lineman moving westward with a speed of 4.8 m/s. The two players collide and stick together, moving at the same velocity after the collision. Determine the post-collision velocity of the two players. [0.842 m/s]