Aball which is dropped from the top of a building strikes the ground with a speed of 30m/s. assume air resistance can be ignored. the height of the building is approximately

               h= 45.87 m.

Explanation:

Data given:

Vf= 30m/s ,     and we know that g = 9.8 m/s²    

The ball has an initial velocity of zero      Vi = 0 m/s²    

To Find:

Height of the building = ?

Solution:

       According to 3rd law of the motion;

                                      2aS= Vf² - Vi²                      ( S= h , a=g)

                                     2*9.81*h = (30)² - (0)²

                                      h= 45.87 m.