Question

A third class lever has a mechanical advantage of <1. What is an example of a third class lever and why use it?

A) pulley; changes direction
B) baseball bat; increases velocity
C) car jack; increases the weight it can lift
D) wheel barrow; makes it easier to move a load

Answer 1

B.) Baseball bat; increases velocity

All third class levers have a mechanical advantage less than 1. Since the output end has a longer distance from the fulcrum than the input point, the output end moves at a greater velocity than the input point. Because of this, third class levers are commonly used when trying to hit an object with as much velocity as possible.

Answer 2

Baseball bat. The handle of the bat is the fulcrum. Exerting a force from the handle supplies the input force just near the middle, while the other end of the baseball bat pushes the ball with the output forces. The input force is greater than the output force but the output load is able to move farther, and this increases the ball's velocity.