Simple Machines Study Guide Answer Key
Directions: Fill in the blank
1. Anything that makes work easier and has few or no moving parts is a simple machine.
2. A bar that pivots on a fixed point is a lever.
3. Two inclined planes placed back to back form a wedge.
4. A wheel with a rope that goes around it is a pulley.
5. Threads wrapped around a post make up a screw.
6. A slanted surface that makes it easier to move an object is an inclined plane.
7. When you use a shovel to pry up an object, the ground acts as a fulcrum.
8. Using force to move an object is known as doing work.
9. All machines need energy to make them work.
10. Simple machines make work easier by trading distance for effort force.
11. Explain how the concept defined in question 10 works for levers.
The longer the lever handle you use the less effort force you need to lift the load. The fulcrum
needs to be near the load.
12. What is gravity? The force that pulls all objects to the center of the Earth
13. What is friction? A rubbing force that slows things down, often causing heat
14. Which of the following materials would have the least friction sliding down an inclined
plane? Which would have the most friction? Explain why.
Plastic block, sponge block, ice block, sandpaper block
The ice block would have the least frictions because it has a smooth surface and as it melts
against the warmer surface the liquid water makes a smoother layer between the ice and
the ramp.
The sandpaper would have the most friction because it is a rough surface.
15. Which of the following is an example of work?
Packing a lunchbox it is the only one where anything is being moved
16. What type of simple machine is a nutcracker?
Lever
17. What simple machine can you use to lift a can of paint to the second floor as you stand on
the ground? Pulley
18. What simple machine is made up of an inclined plane (threads) that winds around a post?
Screw
19. Which of these objects at a playground is an example of a lever?
Seesaw