Question

Marjorie drops an object from a height of h meters, and it hits the ground with a velocity of v m/s, as given by the function v equals the square root of 19.6 h. If the velocity of the object is 68.6 m/s, what was the height of the object before it was dropped? Round your answer to the nearest tenth.

Answer 1

Answer:

240.1 m

Explanation:

Potential energy  ( mgh)  is fully converted to Kintetic energy ( 1/2 mv^2)

  equate them

mgh = 1/2 mv^2     divide by 'm'

gh = 1/2 v^2

9.8 h = 1/2 v^2

    19.6 h = v^2         v = sqrt ( 19.6h)     (as given)

                               68.6 = sqrt (19.6 h)     solve for h = 240.1 m