A ball is thrown vertically upwards with a velcotiy of `20 ms^(-1)` from the top of a multi-storey building. The height of the point fromwher the ball is thrown if 25m from the ground. (a) How high the ball will rise ? And (b) how long will it be before the ball hits the ground ? Take. `g=10 ms^(-2)`.

Answer

(i) 20 m (ii) 5s

Explanation

(i) Height =upward area under v-t curve `=20 m`

(ii) Total time of flight `=2+3=5` sec