## a ball is projected horizontally from the top of a hill with a velocity of 30 m per second if it reaches the ground 5 seconds later the heig

Question

a ball is projected horizontally from the top of a hill with a velocity of 30 m per second if it reaches the ground 5 seconds later the height of the hill is​

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3 months 2021-07-19T22:28:04+00:00 2 Answers 10 views 0

## Answers ( )

The height of the hill is 125m.

Explanation:

Since the ball is projected horizontally from the top of a hill, there is no vertical component of the velocity of projection. Therefore, so far as motion in the vertical direction is concerned, the ball is just dropped, ie its initial velocity u is merely 0 m/s. It reaches the ground after 5 seconds from the moment of projection, under the action of accerelation due to gravity.

Using,

s = u t + ½ a t². In this expression u= 0 m/s, a = 10m/s², t = 5 s. Substituting in the equation we get,

s = 0× t + ½ ×10 m/s²× 5²s²= 5× 25 m = 125m.

2. The height of the hill is 125m.