A lever is a classic example of which type of simple machine?

A lever is a classic example of which type of simple machine?

• A. Pulley
• B. Inclined plane
• C. Lever
• D. Wheel and axle

Answer: (C)

A lever is a simple machine that uses a pivot point, called a fulcrum, and a rigid bar to move a load with less effort. When you push on the bar at a certain distance from the fulcrum, you create torque. The farther your effort is from the fulcrum, the greater its moment (torque) and the easier it is to lift the load on the other side. In balance, effort × distance from the fulcrum equals load × its distance from the fulcrum. This shows how a lever multiplies force or distance. This is different from the other options: a pulley changes the direction of a force with a wheel and rope; an inclined plane lets you raise a load by moving it along a slope; and a wheel and axle uses rotation of interconnected circles to magnify motion or force. Real-world examples include seesaws and crowbars. So, a lever correctly matches the description of a simple machine that uses a fulcrum and a rigid bar to trade force for distance.

A lever is a simple machine that uses a pivot point, called a fulcrum, and a rigid bar to move a load with less effort. When you push on the bar at a certain distance from the fulcrum, you create torque. The farther your effort is from the fulcrum, the greater its moment (torque) and the easier it is to lift the load on the other side. In balance, effort × distance from the fulcrum equals load × its distance from the fulcrum. This shows how a lever multiplies force or distance.

This is different from the other options: a pulley changes the direction of a force with a wheel and rope; an inclined plane lets you raise a load by moving it along a slope; and a wheel and axle uses rotation of interconnected circles to magnify motion or force. Real-world examples include seesaws and crowbars.

So, a lever correctly matches the description of a simple machine that uses a fulcrum and a rigid bar to trade force for distance.