Question

a peeble is thrown vertically upwards and rises to a height of 19.6m find the time taken by the ball to reach max height ​

Answer 1

S = 19.6 m. U = ? V = 0

s = ut +1/2 gt^2 (let g = 10m/s)

19.6 = ut + 5t^2 ---- 1

v = u + gt

0 = u + 10t --- 2

Substituting value of u in equation 2, we get

u = -10t

Substituting value of u in equation 1, we get,

19.6 = -10t^2 + 5t^2

- 5t^2 = 19.6

t^2 = - 3.92 (Squares cannot be negative. Hence take mod value)

t = √3.92 = 1.97 seconds or 2 seconds.

corrections in your question :-

• u is not given.
• the values cannot be negative.
• Please repost the question again with a better question framework.