Which device is a simple machine?

Which device is a simple machine?

• A. Lever
• B. Computer
• C. Refrigerator
• D. Bridge

Answer: (A)

A simple machine helps us do work more easily by changing the size or direction of a force. A lever fits this idea because it’s a rigid bar that pivots on a fulcrum. When you push down on one end, you can lift a heavier load on the other end with less effort, since the lever lets you trade distance moved for a bigger force on the load. The other items aren’t simple machines: a computer and a refrigerator are complex devices made of many parts, and a bridge is a structure, not a tool that multiplies force. So the lever is the simple machine.

A simple machine helps us do work more easily by changing the size or direction of a force. A lever fits this idea because it’s a rigid bar that pivots on a fulcrum. When you push down on one end, you can lift a heavier load on the other end with less effort, since the lever lets you trade distance moved for a bigger force on the load. The other items aren’t simple machines: a computer and a refrigerator are complex devices made of many parts, and a bridge is a structure, not a tool that multiplies force. So the lever is the simple machine.