Question

An inclined plane is 100 m long and at an angle of 20 degrees to the

horizontal. The AMA of the slope is two. Calculate:

a) the effort required to push a 72 underline C N block up the slope b) the ideal mechanical advantage c) the efficiency of the slope.

Answer 1

Explanations & Calculation

• Mechanical advantage of an incline is

$\qquad\qquad \begin{aligned} \small MA&=\small \frac{mg}{F}\\ \end{aligned}$

• Using this,

$\qquad\qquad \begin{aligned} \small F_{actual}&=\small \frac{72\,N}{2}=36\,N\\ \\ \small IMA&=\small \frac{mg}{mg\sin\theta}=\frac{1}{\sin\theta}=\frac{1}{\sin20}\\ &=\small 2.9(>AMA) \end{aligned}$