Name: Class: Date: Power, Work and Machines Test Indicate whether the statement is true or false. 1. Any push or pull that is exerted on matter is called a force. a. True b. False 2. Power is the rate at which work is done. a. True b. False 3. The unit of power is the watt. a. True b. False 4. Under certain conditions, it is possible to get more work out of a machine than you put into it. a. True b. False 5. Work is measured in joules. a. True b. False 6. There are 6 types of simple machines. a. True b. False 7. A force at any angle to the direction of motion can perform work. a. True b. False Indicate whether the statement is true or false. If it is false, change the identified word(s) to make the statement true. 8. The ideal mechanical advantage includes all real forces. _______________ 9. Tweezers are an example of a type of lever. _______________ Indicate the answer choice that best completes the statement or answers the question. 10. The rate at which work is done is called ____. a. efficiency b. effort time c. force d. power 11. An inclined plane with one or two sloping sides forms a machine called a ____. a. pulley b. lever c. ramp d. wedge Powered by Cognero Page 1 Name: Class: Date: Power, Work and Machines Test 12. Which of the following is NOT a way that a machine makes work easier to do? a. change the size of a force b. change the type of a force c. change direction of a force d. change distance a force acts 13. Which is the force that results from use of a machine? a. input force b. output force c. input work d. output work 14. ​ You put in 20 joules of work moving a chair one-way, and it takes 20 joules moving it back, this is an example of _______. a. work in = work out b. friction c. bernoulli's principle d. effort distance 15. Joe is using a crowbar to remove a tree stump. He applies 2066 J of work to the crowbar. The output work of the crowbar is 1240 J. What is the efficiency of the crowbar? a. 60% b. 67% c. 17% d. 10% 16. Cristina slid her book over on her table. Which type of energy is transferred to the book? a. kinetic energy b. potential energy c. kinetic and potential energy d. No energy is transferred. 17. A machine that changes only the direction of a force, such as a single pulley, has a mechanical advantage of ____. a. 1 b. 2 c. 10 d. 100 18. Lifting an object transfers what kind of energy to the object? a. chemical b. kinetic c. potential d. both b and c 19. Power is work divided by _____. a. time b. force c. distance d. speed 20. Which of the following is NOT an example of a wheel and axle? a. screwdriver b. door knob c. pencil sharpener d. screw Powered by Cognero Page 2 Name: Class: Date: Power, Work and Machines Test 21. Which one of the following is NOT an example of work being done? a. Molly holding a barbell above her head perfecting still for 10 minutes. b. pushing a box from the bottom of a hill to the top of the hill c. pulling a sled across a field covered with snow d. lifting a bookbag off the floor 22. Parker pushes a chair 5 meters with a horizontal force of 20 Newtons? a. 4 joules b. 100 joules c. 4 newtons d. 100 newtons 23. Jake lifted a book off the desk. Which type of energy is transferred to the book? a. kinetic energy b. potential energy c. kinetic and potential energy d. No energy is transferred. 24. A bar that is free to pivot about a fixed point is a ____. a. fulcrum b. lever c. ramp d. wedge 25. What is the ideal mechanical advantage of a wedge that is 0.15 meters long and 0.05 meters high? a. 0 b. 1 c. 2 d. 3 26. An inclined plane wrapped around a cylinder post is a ____. a. lever b. ramp c. screw d. wedge 27. Which of the following, by scientific definitions is NOT work? a. lifting boxes of books b. pedaling on your bike c. holding a book over your head perfecting stil for 5 minutes d. pushing a chair across the room 28. A carpenter applies 475 N to the end of a crowbar. The force exerted on the board is 950 N. What is the mechanical advantage of the crowbar? a. 1 b. 2 c. 3 d. 4 29. Kaelyn does 25 J of work in 5.0 s carrying her clean clothes upstairs. How much power did Karla use on the clothes? a. 125 W b. 100 W c. 5.0 W d. 4.0 W Powered by Cognero Page 3 Name: Class: Date: Power, Work and Machines Test 30. ​ A screw driver opening a paint can is an example of a a. ​lever b. ​pulley c. ​wheel d. ​axle Powered by Cognero Page 4 Name: Class: Date: Power, Work and Machines Test Answer Key 1. True 2. True 3. True 4. False 5. True 6. True 7. False 8. False - The ideal mechanical advantage is the mechanical advantage if no friction existed. 9. True 10. d 11. d 12. b 13. b 14. a 15. a 16. a 17. a 18. d 19. a 20. d 21. a 22. b 23. c 24. b 25. d 26. c Powered by Cognero Page 5 Name: Class: Date: Power, Work and Machines Test 27. c 28. b 29. c 30. a Powered by Cognero Page 6.