Question

Displacement of ball with respect to ground during its flight would be

• A. 16.25 m
• B. 8.76 m
• C. 20.24 m
• D. 30.56 m

Answer 1

The correct option is D 30.56 m

In $t=2.13s$, we find out the displacement of the ball with respect to ground.

Initial velocity of ball with respect to elevator=$15m/s$upwards.

Velocity of elevator at the instant of throw=$10m/s$ upwards.

Hence initial velocity of ball with respect to ground=$25m/s$upwards

Appying $s=ut+\frac{1}{2}a{t}^2$

$=\left(25\right)\left(2.13\right)-\frac{1}{2}\left(10\right)\left({2.13}^2\right)=-30.56m$upwards

Hence the displacement is $30.56m$ downwards.