Question

A ball released from a height falls $5m$ in one second. In 4 seconds it falls through (Take $g=10m{s}^{-2}$):

• A. $20m$
• B. $1.25m$
• C. $40m$
• D. $80m$

Answer 1

The correct option is D $80m$

Since $s=ut+\frac{1}{2}gt{}^2$, where $u$ is initial velocity $\&a$ is acceleration.
Given: $u=0\&a=g$
So, distance travelled in 4 sec is,
$s=\frac{1}{2}\times 10\times 16=80m$