Question

A ball is released from a height and it reaches the ground in 3 s. If g= 9.8 m s^-2 Find : 
the velocity with which the ball will strike the ground .

Answer 1

Let 'S' be the height.

Time taken, t = 3s; g = 9.8 m/s²

Initial velocity, u = 0 (because the body starts from rest)

Let 'v' be the velocity with which the ball strikes the ground.

Using the third equation of motion,

v² - u² = 2gs

or, v² - 0² = 2(9.8) (44.1)

or, v² = 864.36

or, v = 29.4 m/s