Forces and Newton’s Laws Review 1. What is fluid friction? What are the 2 main substances that exhibit this type of friction? 2. How can a lubricant “control” friction? Why would this be helpful? 3. If your go-cart weighs 500 kg, what is the force you will have to apply to accelerate it at 1.5 m/s2? 4. An automobile is at rest on a level road. This car will remain at rest until? 5. The unit of force is? Mass? Acceleration? 6. Which law is in control of a spacecraft which cruises through space at a constant speed without using any fuel? 7. If you were to travel to a different planet, would your mass change? What about your weight? 8. An unhappy individual is trying to slide a 100 kg desk across a wooden floor. He pushes with a force of 800 N but the desk does not move. One can conclude that the force of friction is? 9. A net force of 5000 N can give accelerate a 2000 kg car. How much net force would be required to give the same acceleration to a 4000 kg truck? 10. The force of gravity acting on an object is called its? 11. Which of Newton’s 3 Laws applies: a. When you put a book on a table the table pushes on the book b. A person is pushed forward into their seatbelt when a car stops c. A larger car takes more force to move d. A person takes more force to move e. A person leans on a wall and the wall pushes back f. A brick sits on a table until you push on it 12. What is an action that causes motion called? 13. What is a force pulling all objects toward each other called? 14. What is the total amount of matter in an object called? 15. What is the ability of an object to resist change of motion called? 16. Number these from least to most inertia: a baseball, a small car, a truck, a feather, a large train. 17. A sled is being pulled to the left by 5 dogs; each dog is pulling with 6 N of force. Find the net force. 18. A 20 kg bike accelerates at 10 m/s2. With what force was the person pedaling? 19. A 2 N and 6 N forces pull on an object to the right and a 4 N force pulls to the left a 0.5 kg object. What is the net force on the object? 20. Which law governs why a golf ball will go farther than a baseball if each is hit with the same amount of force? 21. An object’s _______ is what makes it difficult to stop or divert the object. 22. Without friction, an object could keep going forever. True or false. 23. What is it called when 2 surfaces slide over each other? 24. Which 2 forces affect nearly all motion? 25. When forces are added together or subtracted from each other, this is called?