A ball is projected from the point O with velocity 20 ~m / s at an angle of 60^ with horizontal as shown in the figure. At highest point of its trajectory, it strikes a smooth plane of inclination 30^ at point A . The collision is perfectly inelastic. The maximum height from the ground attained by the ball is

Step-by-step solution

Speed of ball before collision is v=u 60^ =20 1 2 =10 ~m / s Since, collision is perfectly inelastic ( e=0 ), so the ball will not bounce. It will move along the plane with velocity v^ =v 30^ = 10 3 2 =5 3 ~m / s Maximum height attained by the ball aligned H & = u^2 ^2 60^ 2 g + v^ 2 2 g H & = (20)^2 ( 3 2 )^2 20 + (5 3 )^2 20 & = 300 20 + 75 20 =18.75 ~m aligned