question_answer

  To find the height of a bridge over a river, when a stone is dropped freely in the river from the bridge. The stone takes 2 s to touch the water surface in the river. Calculate the height of the bridge from the water level (g = 9.8 m/s2).

Answer:

                  Initial velocity of the stone, u = 0 Time taken, t = 2s Acceleration due to gravity, g = 9.8 m/s Height of the bridge, h = ?                           (1) Using equation                      (1)  (1) Thus, the height of bridge above the water level is 19.6 m.