Which of the following is the reason a lever is used in a shovel?

A. a lever is used to decrease effort force

B. a lever is used to decrease resistance force

C. a lever is used to increase resistance force

D. a lever is used to increase the effort force

Which of the following is the reason a lever is used in a shovel?

D. a lever is used to increase the effort force

The figure shown below illustrates a lever being used to lift a weight W.

The applied force is F.

In order to lift the weight, the minimum applied force is

F*b = W*a

F = (a/b) W

When the ratio a/b < 1, then the applied force is less than the weight.

The principle behind the use of a lever is to keep the ratio a/b small in order to decrease the effort force.

Answer: A

A lever is used to decrease effort force.