CP PHYSICS Name: __________________________ NEWTON’S LAWS OF MOTION REVIEW 1. Give the names of Newton’s three laws and state what each law means: 1st: ______________________________________________________________ ______________________________________________________________ 2nd: ______________________________________________________________ ______________________________________________________________ 3rd: ______________________________________________________________ ______________________________________________________________ 3. What unit is used for all forces? __________________ 4. What is the relationship between mass and weight? 5. What is the relationship between mass and acceleration? 6. What is the relationship between force and acceleration? 7. What happens to the acceleration of an object if more force is applied? 8. What happens to the acceleration of an object if the mass increases? 9. What velocity must a falling object have to maintain an orbit around Earth? 10. What distance from Earth’s surface do most satellites have to be located? 11. What two factors affect the air resistance experienced by an object? 12. What is meant by the net force that acts on an object? CP PHYSICS, NEWTON’S LAWS OF MOTION REVIEW, page 2 13. If the forces exerted on an object are 50 N in one direction and 30 N in the opposite direction, what is the net force exerted on the object? 14. Forces of 10 N and 20 N in the same direction act on an object. What is the net force on the object? 15. How much air resistance acts on a 100 N bag of nails that falls at its terminal velocity? 16. If you hit a wall with a force of 200 N, how much force is exerted on you? 17. What is free fall? 18. What occurs during non-free fall? 19. For the following, tell whether the statement matches Newton’s 1st, 2nd, or 3rd Law. ____ a. Things tend to keep doing what they are doing. ____ b. When the road is covered with ice, cars tend to keep going in a straight line rather than making a curve. ____ c. Using aluminum instead of steel makes it possible to trim 477 lbs. off a typical 3500 lb. car. The less weight (or mass) of a car, the less fuel it takes to make it go. ____ d. One reason it is so painful to stub your toe against a rock is that the rock hits back. ____ e. To every action there is an equal and opposite reaction. ____ f. Forces tend to accelerate things while mass tends to resist acceleration. ____ g. Boxers often experience hemorrhaging because their brain slams into their skull repeatedly during matches. CP PHYSICS, NEWTON’S LAWS OF MOTION REVIEW, page 3 ____ h. Whiplash may occur when sitting in a car which is hit from behind, especially if headrests are not in place. ____ i. F = ma ____ j. Law of acceleration ____ k. action-reaction ____ l. It takes more force to accelerate a semi truck than a compact car. ____ m. Forces always occur in pairs. ____ n. An astronaut pushed out of a spacecraft will continue to move in a straight line at constant speed forever. ____ o. If you blow up a balloon and release it, the balloon flies away. 20. The following statements are FALSE. Change the incorrect term to make the statement correct! a. It would be just as hard to lift a car on the moon as it is to lift the same car on Earth. b. A baseball bat hits a ball with a force of 100 N. The bat slows down a bit because the ball exerts a resisting force against the bat of more than 100 N. c. The acceleration of an object is directly proportional to its mass. d. A ball falling from a great height will reach terminal velocity when the force of air resistance equals its mass. e. Newton’s third law deals with two forces acting on one object. f. If a light object and a heavy object are dropped together in a vacuum, the heavy object will hit bottom first. g. When an object is at rest, its inertia tends to make it move. h. If there is no force acting on an object, its motion will be one with increasing acceleration. i. The Newton is the unit for mass in the metric system. CP PHYSICS, NEWTON’S LAWS OF MOTION REVIEW, page 4 j. Assume that you are driving down a straight road at constant speed. A small ball is tied on the end of a string hanging from the rearview mirror. When you apply the brakes, the ball will swing backward. 21. If a car starts from rest and reaches a velocity of 20 m/s in 5.0 seconds, what is its average acceleration? 22. What is the force needed to accelerate a 205 kg object at 3.91 m/s2? 23. What is an object’s acceleration if it has a mass of 120 kg and a force of 2350 N acts on it. 24. A man whose mass is 118 kg is taken to a planet where his weight is 2900 N. What is the planet’s acceleration due to gravity? 25. What is the weight of a 688 kg bookcase? 26. A woman whose mass is 80 kg on Earth travels to another planet where the acceleration due to gravity is 3.4 m/s2. What is the mass of this woman on the other planet? 27. A care package weighing 225 N reaches terminal velocity as it falls to the ground. What is the force of air resistance on the package?