Question

A force of 50N exerted over a distance of 3.0m causes a block having a mass of 20kg to move 1.0m find the AMA; the IMA; efficiency.

Answer 1

Find the actual mechanical advantage:

$$AMA=\frac{F_1}{F_2}=\frac{50}{20·9.8}=0.26.$$

The ideal mechanical advantage:

$$IMA=\frac{D_1}{D_2}=\frac13=0.33.$$

Efficiency:

$$\eta=\frac{AMA}{IMA}=0.77.$$