Question

A fruit is dropped from a height of 20 m. Find the velocity with which it would hit the ground.

• A. $40m{s}^{-1}$
• B. $50m{s}^{-1}$
• C. $20m{s}^{-1}$
• D. $30m{s}^{-1}$

Answer 1

The correct option is C $20m{s}^{-1}$

Given:
Displacement, $s=-20m$
Initial velocity, $u=0$

Acceleration due to gravity, $g\approx -10m/s^2$
Upward direction is taken as positive.

From the third equation of motion,
$v^2=u^2+2as$
$v^2=0^2+2\times (-10)\times -20$
$v=20ms{}^{-1}$