Question

A body of mass $2kg$ is dropped from a building of height $5m$. The maximum kinetic energy the 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 $g=10m/s^2$ and $h=5m$

Putting these values we get, $v=10m/s^2$​

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