Question

A person is standing on a trolley which moves horizontally with uniform velocity $2\hat{i}$m/s. At t =0 a ball with velocity ($2\hat{j}$) m/s wrt trolley. Displacements of ball when it returns to initial horizontal of ball when it return to initial horizontal level is the

• A. 0.6 m
• B. 0.2 m
• C. 0m
• D. 0.8 m

Answer 1

The correct option is D 0.8 m

The trolley is moving with velocity = $2\hat{i}$ and a ball in thrown up with velocity $=2\hat{j}m/s$.

Wrt tp trolley, the ball completes a projectile motion whose range is given by:

$R=\frac{2u_x{u}_y}{g}$

As initial velocity $\overrightarrow{u}=-2\hat{i}+2\hat{j},$ so,

$R=\frac{2\times 2\times 2}{10}=0.8m$

The ball return to same horizontal after computing a range of, $R=0.8m$