Name ______

Period ______

Chapter 9 Homework

  1. In a car crash, why it is advantageous for an occupant to extend the time during which the collision is taking place?
  1. If the time of impact in a collision is extended by 4 times, by how much is the force of impact altered?
  1. Why is it advantageous for a boxer to ride with the punch? Why is it disadvantageous to move into an oncoming punch?
  1. Why is the force of impact greater in a collision that involves bouncing?
  1. Which has the greater mass: a heavy truck at rest or a rolling skateboard? Which has the greater momentum?
  1. A car moving at 12 m/s has a mass of 600 kg. What is the car’s momentum?
  1. A car moving at 23 m/s has a mass of 48 kg. What is the car’s momentum?
  1. A person running has a momentum of 500 with a mass of 80 kg. What is the runner’s speed?
  2. A person running has a momentum of 45 with a mass of 6 kg. What is the runner’s speed?
  3. A bowling ball that travels at 1.5 m/s has a momentum of 37.5 what is the mass of the bowling ball?
  1. A bowling ball that travels at 5 m/s has a momentum of 60 what is the mass of the bowling ball?
  2. A car weighs 7840 N. What is it’s mass? The car’s velocity is 25m/s eastward. What is it’s momentum?

The car was accelerated from rest to 25 m/s by a force of 1000N. How long did the force have to act to give the car this velocity?

  1. A force of 10 N acts on a body for 10 seconds. What is the body’s change in momentum? If the mass of the body was 3 kg was what it’s change in momentum?
  1. A net force of 2000N acts on a rocket of mass 1000kg. How long does it take this force to increase the rocket’s speed from 0 m/s to 200 m/s?
  1. Young brother’s mass is 35.6 kg, and he has a 1.3-kg skateboard. What is the combined momentum of your brother and his skateboard if they are going 9.50 m/s?
  1. A hockey player makes a slap shot, exerting a constant force of 30.0 N on the hockey puck for 0.16 s. What is the magnitude of the impulse given to the puck?
  1. A hockey puck has a mass of 0.115 kg and is at rest. A hockey player makes a shot, exerting a constant force of 30.0 N on the puck for 0.16 s. With what speed does it head towards the goal?
  1. A constant force of 6.00 N acts on a 3.00-kg object for 10.0 s. What are the changes in the object’s momentum and velocity?
  1. The velocity of a 625-kg auto is changed from 10.0 m/s to 44.0 m/s in 68.0 s by an external constant force.
  2. What is the resulting change in momentum of the car?
  3. What is the magnitude of the force?
  1. An 845-kg dragster accelerates from rest to 100 km/h in 0.90 seconds.
  2. What is the change in momentum of the car?
  3. What is the average force exerted on the car?
  4. What exerts that force?
  1. Small rockets are used to make tiny adjustments in the speed of satellites. One such rocket has a thrust of 35 N. If it is fired to change the velocity of a 72,000-kg spacecraft by 63 cm/s, how long should is be fired?
  1. A snow-scooter has a mass of 250 kg. A constant force acts on it for 60 seconds. The scooter initial velocity is 6 m/s and its final velocity is 28 m/s. What change in momentum did it undergo? What is the magnitude of the force which acts on it?