Question

Class $3$ levers have mechanical advantage less than $1$.Why are they then even used? $\left[2\text{marks}\right]$

Answer 1

With levers of class $3$, we do not get gain in force, but we get gain in speed, i.e. a larger displacement of load is obtained by a smaller displacement of effort. This is because, in class $3$ levers, the effort arm is smaller than the load arm.
$\left[2\text{marks}\right]$