a ball thrown straight up returns to its starting height in 7.2s.its initial speed was----------m/s.

Solutions

Expert Solution

Answer: Initial speed was 35.3 m/s.

Explanation:

We have given the total time of flight of the ball :

We know that the time required for the ascending journey is same as time for descending journey for any object under the influence of the gravitational force.

Therefore, the time for the ball to reach maximum height is,

At this point i.e. at this maximum height the final velocity of the ball is zero :
At this point the acceleration of the ball is in downward direction and same as acceleration of gravity :

From kinematic equation we have,

Where,

: is the final speed at the maximum height
: is the acceleration of the ball
: is the initial speed of the ball

This was the initial speed of the ball.

genius_generous answered 1 year ago

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