Question

A ball is thrown vertically upward with a speed of 25.0 m/s. (a) How high does it rise?
(b) How long does it take to reach its highest point? (c) How long does the ball take to
hit the ground after it reaches its highest point? (d) What is its velocity when it returns to
the level from which it started?​

Answer 1

Answer:

When the ball reaches the highest point, its velocity will be zero. So final velocity is v=0m/s

Here, the time to reach highest point is equal to time to hit ground from highest point.

Consider upward motion, the acceleration of the ball is a=−g=−9.8m/s

2

(minus for motion opposite to gravity)

If t be the required time.

Using v=u+at,

0=25+(−9.8)t

⟹ t=2.5s

Thus the ball hits the ground after 2.5 seconds after reaching its highest point

Answer 2

a) 2.5s

When the ball reaches the highest point, its velocity will be zero. So final velocity is v =

0 m/s

Here, the time to reach highest point is equal to time to hit ground from highest point.

Consider upward motion, the acceleration of the ball is a = - g = - 9.8 m/s ^ 2 (minus for motion If t be the required time.

opposite to gravity)

Using v = u + at ,

0 = 25 + (- 9.8) * t

Rightarrow t=2.5s

Thus the ball hits the ground after 2.5 seconds after reaching its highest point.