Question

Child drops a ball from a height of 10m assume that its velocity increases uniformly at the rate of 10 metre per second square find the velocity with which the ball strikes the ground and.time taken by the.ball to reach the ground

Answer 1

    ⒶⓃⓈⓌⒺⓇ    

Acceleration(a) = 10 m/s²

Initial Velocity(u) = 0 m/s

Final velocity be 'v' m/s

g = 10 m/s²

Now Using equation of motion:

v² + u² = 2gh

v = √2gh

  = √200

  =  10√2 m s⁻¹

Now, Let the time be 't' sec.

Equation of motion:

  h = ut + 1/2gt²

⇒h = 1/2gt²

⇒t = √(2h/g)

⇒t = √2 sec

∴ Velocity = 10√2 m s⁻¹

∴ Time = √2 second