Question

A boy projects a stone vertically perpendicular to the trolley car with a speed $v$. If the trolley car moves with a constant velocity $u$, the time of flight of the stone is:

• A. $\frac{2v}{g}$
• B. $\frac{u+v^2}{g}$
• C. none of these
• D. $\frac{2u}{g}$

Answer 1

The correct option is C none of these

Resolve the velocity 𝑣 into horizontal and vertical component.

$v_0\sin \theta =v$
$v_0\cos \theta =u$

Time of flight depends on vertical component of velocity.

$T=\frac{2v_0\sin \theta }{g}=\frac{2v}{g}$