A man inside a moving train throwa a baoll vertically upwards . How will the motion of ball appears to a stationary observe (a) inside the train and (b) outside the train?

Explanation

(a) With respect to stationary observe inside the train , ball has only one velocity component , along vertical. So, to him , the ball will appear to move straight , vertically upwards and then downwards .
(b) With respect to observe outside the train , the ball has both components of velocity , horizontal and vertical. So, to him the ball will appear to move in a parabolic path .