Physics, asked by rockband, 1 year ago

A stone is thrown vertically up from the tower of height 25m with a speed of 20m/s time taken to reach the ground?

Answers

Answered by JunaidMirza
2
Velocity when it touches the ground = sqrt(u^2 + 2gH)
= sqrt(400 + (2 × 10 × 25))
= 30 m/s

Time taken by stone = 2u/g + [(v - u)/g]
= [(2 × 20)/10] + [(30 - 20)/10]
= 5 seconds

∴ Total time taken by stone to reach the ground is 5 seconds
Answered by bhavani2000life
4

Answer: [100% CORRECT]

T = 5 seconds

Explanation:

-> We consider the upward direction as positive and downward direction as negative with respect to a point of reference.

Then, u = 20 m/s

= a = g = -10 m/s^2

= s = h = -25 m

From the equation of Motion s = ut + 1.2 at^2

-25 = 20t - 1/2 x 10 x t^2

-25 = 20t - 5t^2

-5 = 4t - t^2

=> t^2 - 4t - 5 = 0

Solving the equation we get,

(t - 5) (t + 1) = 0

t = 5 or -1

t =5 seconds

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