A ball is dropped from the top of a building.In the absence of air resistance,the ball will hit the ground with a speed of 49 m/s.The height of the building is
A)25 m
B)5 m
C)240 m
D)120 m
E)10 m

Question

Quizplus · Accepted Answer

The speed of an object dropped from a height can be found using the equation:

v^2 = 2gh

Where,
v = final speed = 49 m/s (given)
g = acceleration due to gravity = 9.8 m/s^2 (constant)
h = height of the building (unknown)

Substituting the given values in the above equation, we get:

49^2 = 2 x 9.8 x h
=> h = (49^2)/(2 x 9.8)
=> h = 120.05 m (approx.)

Therefore, the height of the building is approximately 120 m. The answer is option D.

A Ball Is Dropped from the Top of a Building