Questions – Impulse and Momentum
1. A 6.00 N force acts on a 1.50 kg
mass for 5.00 seconds. Find:
a) The impulse which acted upon
the mass.
b) what change in momentum is
produced?
c) Calculate the final velocity of the object, if it was initially at rest.
2. For how many seconds would a force of 8.00 N have to act on a 2.00 kg mass in order
to change its velocity from 2 m/s to 7 m/s?
3. If a certain mass has its velocity changed from 6.00 m/s to 7.50 m/s when a 3.00 N
force acts for 4.00 seconds, find the mass of the moving object.
4. What force is necessary in order to change the velocity of a 2.00 kg object from
– 4.00 m/s to +3.00 m/s in 0.10 seconds?
5. A 10.0 kg object is traveling with a velocity of 6.00 m/s. It is acted upon by a force
of – 5.00 N for a time of 4.00 seconds. What is the final velocity of the object?
6. A 2.00 kg ball moving with an initial velocity of +3.00 m/s is acted upon by a
constant force F, for a period of 3.00 seconds. After the interaction, the ball is
moving with a velocity of – 6.00 m/s. Find F.
7. Calculate the momentum of cart 1 – 2.00 kg cart moving at 30 m/s North.
Calculate the momentum of cart 2 – 1.50 kg cart moving 40.0 m/s South.
Can you say their momentums are equal? Why or why not?
8. A golf ball of mass 100 g, initially at rest, is struck by a club. After the impact, the
ball moves off with a velocity of 50.0 m/s. If the ball and club are in contact for
5.00 x 10-3 seconds, what was the average force acting on the ball?
-20 m/s
18 m/s
9. A billiard ball of mass 200 g is thrown against a steel plate and
it rebounds as shown. Find the change in momentum of the body.
10. A 3.00 kg object initially is traveling with a velocity of 4.00
m/s.
a) What is its momentum?
b) If a 5.00 N force acts to the right for 1.80 seconds, what is its new momentum?
c) What is the final velocity of the object?
11. An 8.00 kg object is moving at 4.00 m/s.
a) Find Pi
b) If a force of – 5.00 N acts for 4.00 seconds, find the final momentum of the
object.
c) What is its final velocity?
Answers
1. 30 Ns
b) 30 Ns
c) 20 m/s
2. 1.25 s
3. 8 kg
4. 140 N
5. 4 m/s
6. –6 N
7. 60 kgm/s North, 60 kgm/s South, No not equal
8. 1000 N
9. 7.6 kgm/s
10. a) 12 kgm/s
b) 21 kgm/s c) 7 m/s
11. a) 32 kgm/s
b) 12 Ns
c) 1.5 m/s
see http://cabennet.mvsd.ca/PHYS40S/Momentum/Impulse_and_Momentum_solns.pdf
for solutions