Question

A ball is thrown vertically upwards with velocity 20 m/s. find the time taken for the ball to reach a height of 20m​

Answer 1

Answer:

⇝ Given :-

• A ball is thrown vertically upwards with velocity 20 m/s.

• It reaches a height of 20 m.

⇝ To Find :-

• Time taken by the ball to reach a height of 20 m.

⇝ Solution :-

Here,

• Initial Velocity = u = 20 m/s

• Acceleration = a = - g = - 10 m/s²

• Height = s = 20 m

Let Time Taken by Ball = t second

❒ We Have 2nd Equation of Motion as :

• s = ut + 1/2at^2

✧ Putting Given Values In above ;

-> 20 = 20× t + 1/2 × (-10) ×t^2$t^{2}$

-> 20 = 20t - 5t^2

->5t^2 - 20t + 20 = 0

viding whole equation by 5

-> t^2 - 4t + 4 = 0

-> t(t-2) (t -2) = 0

--> t = 2s

Therefore,

Time taken = 2 second

⇝ Additional Information

✿ Three Equations of Motion :

✿ v = u + at

✿ s = ut + 1/2 at^2

✿ v^2 - u^2 = 2as

Hope its helps you

Thanks !!

@Jiyaa021