Question

A ball is thrown vertically upwards with a velocity 'u' from the balloon descending with velocity v. The ball will pass by the balloon after time.

• A. $\frac{u-v}{2g}$
• B. $\frac{u+v}{2g}$
• C. $\frac{2(u-v)}{g}$
• D. $\frac{2(u+v)}{g}$

Answer 1

Answer: (D)

$\frac{2(u+v)}{g}$

If we look from frame of balloon the ball is thrown with velocity $u+v$
and therefore it will pass the balloon after its relative time of flight.
$t=\frac{2(u+v)}{g}$