Projectile Motion

A ball is thrown from a point with a speed at an angle of projection From the same point and at the same instant, a person starts running with a constant speed to catch the ball. Will the person be able to catch the ball? If yes, what should be the angle of projection?

A ball rolls of the top of a stair way with a horizontal velocity If the steps are metre high and b metre wide, the ball will hit the edge of the nth step, where is