Simple Machines — Answer Key
Part A: Fill in the Blank
Write the missing word or number on each line.
1. A ramp is an example of an inclined plane.
An inclined plane is a flat, sloped surface that reduces the effort needed to move objects to a higher level.
2. A pulley changes the direction of a force using a rope and a grooved wheel.
A pulley is a simple machine that uses a rope around a wheel to change the direction of a force, making lifting easier.
3. The fixed point on which a lever turns is called the fulcrum.
The fulcrum is the support point where a lever balances and rotates to move a load.
4. A screw is really an inclined plane wrapped in a spiral shape.
A screw is essentially an inclined plane wrapped around a cylinder in a spiral shape, which helps it push into materials.
5. A knife blade is an example of a wedge because it splits things apart.
A knife is a wedge because it has a thin, sharp edge that splits or cuts through materials.
6. A steering wheel is an example of a wheel and axle.
A doorknob works as a wheel and axle — turning the larger knob (wheel) rotates the smaller shaft (axle) to open the door.
7. Simple machines reduce the amount of force needed to do work.
Simple machines reduce the amount of force needed to do work, though the total work remains the same.
8. A wheelchair ramp makes it easier to move up by increasing the distance.
A longer ramp means you travel a greater distance, but the force needed to push a load up is reduced.
9. A bottle cap is removed by turning, which uses a screw simple machine.
A screw has spiral ridges (threads) wrapped around a rod that grip into materials and hold them firmly together.
Part B: Matching
Match each item on the left to the correct answer on the right.
1. Match each item to its correct answer.
Lever
→ Bar that turns on a fulcrum
Rope and wheel to lift loads
Inclined plane
→ Flat sloping surface
Bar that turns on a fulcrum
Wedge
→ Thin edge that splits things
Flat sloping surface
Pulley
→ Rope and wheel to lift loads
Thin edge that splits things
A lever is a bar that turns on a fulcrum, an inclined plane is a flat sloping surface, a wedge has a thin edge that splits things, and a pulley uses a rope and wheel to lift loads.