Question

A student is standing on a train travelling along a straight horizontal track at a speed of $10\text{m/s}$. The student throws a ball into the air along a path, that he sees to make an initial angle of ${60}^{\circ }$ with the horizontal along the track. The professor standing on the ground observes the ball to rise vertically, the maximum height reached by the ball is

Answer 1

$V_{bt}\cos {60}^{\circ }=10$
$V_{bt}\sin {60}^{\circ }=V_{bg}$

The direction in which the ball is thrown is independent, because the ball will reach the same height for every direction.

$V_{bg}=10\sqrt{3}$
$H=\frac{V_{bg}^2}{2g}=\frac{100\times 3}{20}=15\text{m}$