Question

A ball is thrown vertically upwards such that when it reaches half the maximum height it was a velocity of 7 metre per second what is the maximum height attained by the ball?​

Answer 1

Answer:

The answer is 5 meters.

Step-by-step explanation:

If a body is thrown vertically upwards with a velocity of 'u' m/s and the body reaches to a maximum height of 'h' meters. Where v = 0 is the velocity of the body at the maximum height.

Then from the equations of motion we get ,

v² = u² - 2gh [ 'g' being the acceleration due to gravity ]

⇒ 0² = u² - 2gh

⇒ u² = 2gh → (1)

In this case , velocity of the body at the half of the maximum height ( h/2 )  is, v = 7 m/s.

Then , v² = u² - 2g( h/2 )

⇒ 7² = u² - gh

⇒ u² - gh = 49

⇒ 2gh - gh = 49 [ from (1) ]

⇒ gh = 49 ⇒ 9.8 × h = 49 ⇒ h = 5 meters.