Question

A body of mass 2 kg is dropped from a building of height 5m. The maximum kinetic energy body can attain is

• A. 50 J
• B. 100 J
• C. 150 J
• D. 200 J

Answer 1

The correct option is B

100 J

From $1^{st}$ equation of motion we have, $v^2$ = $u^2$ + 2gh.

As it is dropped so, u = 0 and g = 10 $\frac{m}{s^2}$ and h = 5m.

Putting these values we get, v = 10 $\frac{m}{s}$​.

So, the body would attain the maximum kinetic energy when it strikes the ground, i.e. K.E = $\frac{1}{2}$​ $\times$ m $\times$ $v^2$ ​= $\frac{1}{2}$ $\times$ 2 $\times$ ${10}^2$​ = 100J