Question

A stone is thrown up to a height of 150 m with a velocity of 30m/s after which it falls back to the earth. Calculate u, v, t for going up, t for going down, total distance, total time.​

Answer 1

Given :-

Height attained by body = h = 150 m.

Initial velocity of body = u = 30 ms-¹.

Using third equation of Motion,

v² = u² + 2gh

v² = 900 + 2 × 10 × 150

v = √3900

v = 62.4 ms-¹

While going upward its final Velocity becomes zero.

v = u - gt

10t = 30

t = 3 s

While coming downward,

v - u = gt'

62.4 - 30 = 10t'

t' = 3.24 a

Total time = T = t + t'

T = 3 + 3.24

T = 6.24 s

Total distance = 150 m + 150 m = 300 m