A ball is fired from point `P`, with an initial speed of `50 m s^-1` at an angle of `53^@`, with the horizontal. At the same time, a long wall `AB at 200 m` from point `P` starts moving toward `P` with a constant speed of `10 m s^-1`. Find
(a) the time when the ball collides with wall `AB`.
(b) the coordinate of point `C`, where the ball xollides, taking point `P` as origin.
.

Answer

(a) 5 s;
(b) 150 m ; 75 m.

Explanation

(a) Relative horizontal velocity of ball and wall
=`50 cos 53^@ + 10 = 40 ms^-1`
So time taken: `t = (200)/(40) = 5 s`
(b) x coordinate of point C : `x = (50 cos 53^@) 5 = 150 m`
To find y coordinates :
`y = 50 sin 53^@ xx 5 - (1)/(2) 10 (50)^2 = 75 m`.