Question

Why is the mechanical advantage of a lever of third-order always less than $1$? Give one example of this class of lever.

Answer 1

Mechanical advantage in terms of load arm and effort arm is,

$MA=\frac{Effortarm}{Loadarm}$

1. The mechanical advantage of a class $3$ lever is always less than one since the load arm is always longer than the effort arm.
2. As the mechanical advantage of the speed multiplier is less than one, thus, class $3$ lever is a speed multiplier.
3. One example of class $3$ lever is a fishing rod.