Skills Worksheet Directed Reading B Section: Types of Machines 1. What type of simple machine is a knife? b. wheel and axle d. inclined plane 2. Which of the following is NOT a simple machine? b. airplane c. lever d. screw LEVERS 3. What is the fixed point on a lever called? a. bolt b. pivot point c. fulcrum d. wedge First-Class Levers 4. What do first-class levers always change the direction of? a. input force b. output force c. distance d. fulcrum Holt Science and Technology 18 Work and Machines
Read the description. Then, draw a line from the dot next to each description to the matching lever. 5. first-class lever 6. second-class lever 7. third-class lever PULLEYS 8. Which of the following simple machines has a grooved wheel that holds a rope? b. wedge c. pulley d. wheel and axle Fixed Pulleys 9. Which kind of pulley is attached to something that does not move? a. fixed pulley b. movable pulley c. block and tackle d. simple pulley Holt Science and Technology 19 Work and Machines
Movable Pulleys 10. Which kind of pulley is attached to the object being moved? a. fixed pulley b. movable pulley c. block and tackle d. simple pulley Block and Tackles 11. Upon what does the mechanical advantage of a block and tackle depend? a. amount of input force b. amount of output force c. number of levers d. number of rope segments WHEEL AND AXLE 12. A faucet is what type of simple machine? b. wedge c. wheel and axle d. lever Mechanical Advantage of a Wheel and Axle 13. How do you find the mechanical advantage of a wheel and axle? a. Divide the radius of the wheel by the radius of the axle. b. Divide the radius of the axle by the radius of the wheel. c. Add the radius of the wheel and the radius of the axle. d. Multiply the radius of the wheel by the radius of the axle. Holt Science and Technology 20 Work and Machines
INCLINED PLANES 14. What type of simple machine is a ramp? b. inclined plane c. pulley d. wedge Mechanical Advantage of Inclined Planes 15. How do you find the mechanical advantage of an inclined plane? a. Multiply length of inclined plane by height of inclined plane. b. Divide length of inclined plane by height of inclined plane. c. Add length of inclined plane and height of inclined plane. d. Subtract length of inclined plane from height of inclined plane. Wedges 16. What type of simple machine is a wedge? b. lever c. inclined plane d. wheel and axle Mechanical Advantages of Wedges 17. How do you find the mechanical advantage of a wedge? a. Multiply length of wedge by greatest thickness. b. Divide length of wedge by greatest thickness. c. Subtract length of wedge from greatest thickness. d. Add length of wedge and greatest thickness. Holt Science and Technology 21 Work and Machines
Screws 18. Which of the following is an inclined plane wrapped around a cylinder? a. screw b. nail d. ramp Mechanical Advantage of Screws 19. A jar lid is an example of which simple machine? a. nail b. screw d. ramp COMPOUND MACHINES Read the words in the box. Read the sentences. Fill in each blank with the word or phrase that best completes the sentence. compound machines wedge mechanical efficiency 20. Most compound machines have a low 21. Machines that are made of two or more simple machines are called 22. A can opener is made of a lever, wheel and axle, and a(n) Holt Science and Technology 22 Work and Machines