# Physical Science: Motion, Forces, and Energy, Book M

## Chapter 4: Work and Simple Machines

### Work and Simple Machines

 1. What happens to the total amount of work done when you use a machine compared to not using a machine? Need a Hint? A) It goes to zero. B) It increases. C) It stays the same. D) It decreases. 2. How do input force and output force relate to each other? Need a Hint? A) They are unrelated. B) They are the same. C) They are always different. D) The input is always less than the output. 3. Mechanical advantage is equal to __________. Need a Hint? A) input force times output force B) output force times input force C) output force divided by input force D) input force divided by output force 4. Which is an example of work being done in a scientific sense? Need a Hint? A) lifting a box B) doing homework C) pushing against a stationary box D) carrying a box 5. On what point does a lever pivot? Need a Hint? A) the end B) the fulcrum C) the arm D) the middle 6. What is the scientific formula for work? Need a Hint? A) W = F + d B) W = F/d C) W = F x d D) W = F - d 7. When you climb stairs and then walk down a hallway, in which direction is the work done? Need a Hint? A) in the opposite direction that you walk B) downward C) along the hallway D) upward 8. What does a screw consist of? Need a Hint? A) an inclined plane wrapped around a cylinder B) a wedge wrapped around a pipe C) a lever wrapped around a pole D) a wheel and axle in a vertical position 9. The efficiency of all machines is __________. Need a Hint? A) less than 100 percent B) impossible to calculate C) more than 100 percent D) exactly 100 percent 10. A ramp in a building is an example of which machine? Need a Hint? A) lever B) pulley C) inclined plane D) wedge 11. A drill bit is an example of which type of machine? Need a Hint? A) wheel and axle B) pulley C) lever D) screw 12. Using several pulleys together is known as a __________. Need a Hint? A) wheel and axle B) pulley system C) machine system D) pulley group 13. Power is measured by which units? Need a Hint? A) watts B) newtons C) newton-meters D) joules 14. What happens to the amount of power expended when you are climbing stairs and then climb faster? Need a Hint? A) It increases. B) It decreases. C) It stays the same. D) It stops. 15. Name the four simple machines. Need a Hint? A) plane, lever, screw, and wedge B) screw, lever, wedge, and plane C) wedge, lever, pulley, and wheel D) inclined plane, lever, wheel and axle, and pulley 16. What is the mechanical advantage if 50 J are put in and 200 J are produced? Need a Hint? A) 50 B) 1000 C) 200 D) 4 17. The unit for work is a joule, which is equal to __________. Need a Hint? A) N x m B) N - m C) N + m D) N/m 18. Using an inclined plane allows you to apply __________. Need a Hint? A) a greater force B) the same force C) no force D) a lesser force 19. What is a sign that work is being done? Need a Hint? A) mass B) motion C) matter D) density 20. Which simple machines are found on a hammer? Need a Hint? A) lever only B) plane and lever C) wedge and plane D) screw and pulley