Momentum and Impulse Homework
1. Which of the following statements are true about momentum?
a. Momentum is a vector quantity.
b. The standard unit on momentum is the Joule.
c. An object with mass will have momentum.
d. An object which is moving at a constant speed has momentum.
e. An object can be traveling eastward and slowing down; its momentum is westward.
f. Momentum is a conserved quantity; the momentum of an object is never changed.
g. The momentum of an object varies directly with the speed of the object.
h. Two objects of different mass are moving at the same speed; the more massive
object will have the greatest momentum.
i. A less massive object can never have more momentum than a more massive object.
j. Two identical objects are moving in opposite directions at the same speed.
k. The forward moving object will have the greatest momentum.
l. An object with a changing speed will have a changing momentum.
m. Momentum is not equal to the mass of an object divided by its velocity.
n. The momentum of an object can change.
o. Two objects with the same mass will always have the same momentum.
p. When an object speeds up, it gains momentum.
q. Objects with different masses can’t have the same momentum.
r. Direction does not matter when you are measuring momentum.
s. Momentum can be transferred from one object to another.
t. A tiny bullet can have more momentum than a huge truck.
2. Determine the momentum of a (a.) 60-kg halfback moving eastward at 9 m/s. (b.) 1,000-kg
car moving northward at 20 m/s. (c.) 40-kg freshman moving southward at 2 m/s.
3. A car possesses 20,000 “units” of momentum. What would be the car's new momentum if
a. its velocity was doubled.
b. its velocity was tripled.
c. its mass was doubled (by adding more passengers and a greater load).
d. both its velocity was doubled and its mass was doubled.
4. Among the largest passenger ships currently in use, the Norway has been in service the
longest. The Norway is more than 300 m long, has a mass of 6.9x107 kg, and can reach a
top cruising speed of 33 km/h. Calculate the magnitude of the ship’s momentum.
5. A football player kicks a ball with a force of 50N. Find the impulse on the ball if his foot
stays in contact with the football for 0.01s.
6. Aunt Mary needs to hang a picture in her bedroom. She uses a hammer to drive the nail
into the wall. Find the force exerted by the hammer on the nail if the hammer stays in
contact with the nail for 0.5s and has an impulse of 25Ns.
7. A 0.5kg baseball is being caught, and experiences a 10N force for the duration of 0.1s.
What is the change in velocity of the baseball?
8. Suppose you are traveling in a bus at highway speed on a nice summer day and the
momentum of an unlucky bug is suddenly changed as it splatters onto the front window.
a. Compared to the force that acts on the bug, how much force acts on the bus.
(more) (the same) (less)
b. Although the momentum of the bus is very large compared to the momentum of the
bug, the change in momentum of the bus compared to the change in momentum of
the bug is (more) (the same) (less)
c. Which experiences the greater acceleration (HINT: think of Newton’s 2nd Law)?
(bus) (both the same) (bug)
d. Which, therefore, suffers the greater damage? (bus) (both the same) (the bug of
course!)