Question

From a top of a tower of height 40m a ball is projected upward with a speed of 20m/s at an elevation of 30degree. The ratio of the total time taken by the ball to hit the ground to its Time of flight (time to come back to the point of projection ) is (g=10m/s)

Answer 1

s=−40m,u=+10ms−1,a=−10ms−2

Now s=ut+12at2

=> −40−10t+12×(−10)t2

=> r2−2t−8=0

=> (t+2)(t−4)=0

=> t=−2or4s

The negative value of t is not possible

Hence the ball will hit the ground after 4 s

and find the time of flight by T=2USINTHETA/G

Answer 2

Your answer is 2:1

Explanation:

Hope it helps ↓