Levers

Front

What is a lever?

Back

A lever is a simple machine that consists of a rigid bar that pivots around a fixed point called the fulcrum.

Front

What are the three classes of levers?

Back

The three classes of levers are: 1) First-class lever (fulcrum in the middle), 2) Second-class lever (load in the middle), 3) Third-class lever (effort in the middle).

Front

What is the purpose of a fulcrum in a lever?

Back

The fulcrum is the fixed point around which the lever rotates, allowing the lever to amplify force or distance.

Front

How does a lever reduce the amount of force needed to lift an object?

Back

A lever reduces the amount of force needed by increasing the distance over which the force is applied.

Front

What is an example of a first-class lever?

Back

An example of a first-class lever is a seesaw.

Front

What is an example of a second-class lever?

Back

An example of a second-class lever is a wheelbarrow.

Front

What is an example of a third-class lever?

Back

An example of a third-class lever is a pair of tweezers.

Front

What is mechanical advantage in the context of levers?

Back

Mechanical advantage is the ratio of the output force produced by a machine to the input force applied to it.

Front

How does the position of the fulcrum affect the mechanical advantage of a lever?

Back

The position of the fulcrum affects the mechanical advantage by determining how much force is needed to lift a load; moving the fulcrum closer to the load increases mechanical advantage.

Front

What is the trade-off when using a lever to reduce force?

Back

The trade-off is that while the force needed is reduced, the distance over which the force must be applied is increased.