the momentum of the ball?
kg·m/s1.2 A sport utility vehicle is travelling at a speed of 15.3 m/s. If its momentum has a magnitude of 32,800 kg·m/s, what is the
SUV's mass?
kg1.3 A truck with a mass of 2200 kg is moving at a constant 13 m/s. A 920 kg car with the same momentum as the truck passes it
at a constant speed. How fast is the car moving?
m/s1.4 At a circus animal training facility, a monkey rides a miniature motorscooter at a speed of 7.0 m/s. The monkey and scooter
together have a mass of 29 kg. Meanwhile, a chimpanzee on roller skates with a total mass of 44 kg moves at a speed of 1.5
meters per second. The magnitude of the momentum of the monkey plus scooter is how many times the magnitude of the
momentum of the chimpanzee plus skates?1.5 A net force of 30 N is applied to a 10 kg object, which starts at rest. What is the magnitude of its momentum after 3.0
seconds?
kg·m/sSection 2 - Momentum and Newton's second law
2.1 A golden retriever is sitting in a park when it sees a squirrel. The dog starts running, exerting a constant horizontal force of
89 N against the ground for 3.2 seconds. What is the magnitude of the dog's change in momentum?
kg·m/sSection 3 - Impulse
3.1 A 1400 kg car traveling in the positive direction takes 10.5 seconds to slow from 25.0 meters per second to 12.0 meters per
second. What is the average force on the car during this time?
N
3.2 A cue stick applies an average force of 66 N to a stationary 0.17 kg cue ball for 0.0012 s. What is the magnitude of the
impulse on the cue ball?
kg·m/s
3.3 A baseball arrives at home plate at a speed of 43.3 m/s. The batter hits the ball along the same line straight back to the
pitcher at 68.4 m/s. The baseball has a mass of 0.145 kg and the bat is in contact with the ball for 6.28×10í^4 s. What is the
magnitude of the average force on the ball from the bat?
N3.4 A steel ball with mass 0.347 kg falls onto a hard floor and bounces. Its speed just before hitting the floor is 23.6 m/s and its
speed just after bouncing is 12.7 m/s. (a) What is the magnitude of the impulse of the ball? (b) If the ball is in contact with the
floor for 0.0139 s, what is the magnitude of the average force exerted on the ball by the floor?(a) kg·m/s
(b) N3.5 The net force on a baby stroller increases at a constant rate from 0 N to 88 N, over a period of 0.075 s. The mass of the baby
stroller is 7.4 kg. It starts stationary; what is its speed after the 0.075 s the force is applied?
m/s3.6 A government agency estimated that air bags have saved over 14,000 lives as of April 2004 in the United States. (They also
stated that air bags have been confirmed as killing 242 people, and they stress that seat belts are estimated to save 11,000
lives a year.) Assume that a car crashes and has come to a stop when the air bag inflates, causing a 75.0 kg person moving
forward at 15.0 m/s to stop moving in 0.0250 seconds. (a) What is the magnitude of the person's impulse? (b) What is the
magnitude of the average force the airbag exerts on the person?
(a) kg·m/s
(b) N3.7 Imagine you are a NASA engineer, and you are asked to design an airbag to protect the Mars Pathfinder from its impact with
the Martian plain when it lands. Your system can allow an average force of up to 53,000 N on the spacecraft without damage.
Your Pathfinder mock-up has a mass of 540 kg. If the spacecraft will strike the planet at 24 m/s, what is the minimum time for
your airbag system to bring Pathfinder to rest so that the average force will not exceed 53,000 N?
s