Download Momentum and Impulse

Name: __________________________________________
Physics A
J = FΔt
p = mv
Date:_____________
Momentum and Impulse
J = Δp
FΔt = Δp
FΔt = mvf - mvi
1) A 2250 kg pick-up truck has a velocity of 25 m/s. What is the momentum of the truck?
2) What velocity must a 1210 kg car be traveling at to have the same momentum as the pickup in the previous problem?
3) What is the momentum of an 8 kg bowling ball rolling at 2 m/s?
4) A running football player has a momentum of 500 kg·m/s and a mass of 120 kg. What is his
velocity while running down the field?
5) Can you think of an instance when a jet airliner has the same momentum as the mosquito
mentioned above?
6) A 95 kg rider pedals a 30 kg bike down the street at 23 m/s.
a. What is the momentum of the bike?
b. What is the momentum of the rider?
c. What is the total momentum of the bike and the rider?
7) What is the impulse provided by a baseball bat providing a 450 N force over 0.3 seconds?
8) A rubber bumper provides an impulse of 540 N·s to stop a golf cart.
a. What was the average force provided by the bumper if it acted over 1.2 seconds?
b. What was the average force provided by the bumper if it acted over 0.2 seconds?
9) A 1400 kg car moving at 20 m/s is brought to a stop in 4 seconds. What is the average
force required to stop the car?
Name: __________________________________________
Physics A
Date:_____________
10) The brakes on a 1,000,000 kg train can apply a force of 1.5x106 N. If the train is moving
at 35.7 m/s (roughly 80 mph) how much time is required to stop the train?
11) An impulse is provided by a 250 N force acting for 1.3 seconds. If the impulse acts on a
25 kg mass initially at rest, what is the final velocity of the mass?
12) A baseball pitcher claims he can throw a 0.145 kg baseball with as much momentum as a
speeding bullet. Assume that a 3.00 g bullet moves at a speed of 1.5x103 m/s. What must
the baseball's speed be if the pitcher is correct?
13) What is the final velocity of a 45 kg ice skater moving at 4 m/s if a 10 N force of friction
acts on her for 2 seconds?
14) A 2 kg watermelon traveling at 10m/s (this is about 25 mph) slams into a tree and stops.
The tree does not move.
a. What is the force exerted by the tree on the watermelon if the watermelon comes
to rest in 0.1 seconds?
b. Repeat the above calculation for an impact in which the same watermelon traveling
10m/s comes to stop on a nice large cushy bed of hay, with an impact time of 0.6
seconds.
c. Which situation has a larger impulse on the watermelon? Explain.
d. In which case do you think the watermelon was most damaged? Why ?
15) How does a baseball glove reduce the force a player feels when a fastball is caught?
Remember, the pain a baseball player feels from catching a ball is due to the force he or
she feels when catching the ball.
Name: __________________________________________
Physics A
Date:_____________
16) A 2kg wagon traveling at 8 m/s in one direction finds itself traveling in the opposite
direction at 6 m/s as a result of an impulse lasting 5 seconds.
a. What force was applied?
b.
In what direction was it applied?
17) A 40 N force directed to the East is applied to a 10 kg cart moving West at 4 m/s.
a. What is the cart’s final velocity (speed and direction) if the force acted for 1
second?
b. Repeat if the force acted for 3 seconds.