Question

$\text{(a)}$ Define mechanical advantage of a machine and write down its formula. $\left[2\text{marks}\right]$

$\text{(b)}$ A chestnut can be broken by a nutcracker with a force of $30\text{kgf}$. If the mechanical advantage of the nutcracker is $8$, what is the minimum force to be applied on the nutcracker? $\left[2\text{marks}\right]$

Answer 1

$\text{(a)}$ The mechanical advantage $\left(\text{MA}\right)$ is the measure of how the machine eases the task for which it is operated. It is defined as the ratio of the load to the effort of the machine. $\left[1\text{mark}\right]$

$⟹\text{MA}=\frac{\text{Load}}{\text{Effort}}$ $\left[1\text{mark}\right]$

$\text{(b)}$ Given:
The force that the nutcracker has to apply on the chestnut is the load of the machine, $L=30\text{kgf}$

The mechanical advantage of the nutcracker, $\text{MA}=8$ $\left[0.5\text{mark}\right]$

The force that has to be applied on the nutcracker is the effort of the machine, $E=\frac{L}{\text{MA}}=\frac{30}{8}=3.75\text{kgf}$ $\left[1.5\text{marks}\right]$