Question

A ball is thrown up and attains a maximum height of 100 m its inital speed was

Answer 1

Hello friend....!!!

According to the question it is given that,

H Max = 100 m

And we should find what was the initial speed

We know that,

H = u^2 / 2g

100 * 2g = u^2

√ 100 * 2 ( 10 ) = u

Therefore,

U = √2000

U = 44.7 m/s

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Hope it helps...!!!

Answer 2

Given,

h = 100 m
u = ?

From Netwon's eq. of motion:

v² = u² + 2gh

So, 0 = u² - 2gh [As the body is moving upwards, also the body stops at the end]

Or -u² = -2gh

Or u² = 2gh

Or u = √2gh

Or u = √2 × 9.8 × 100

Or u = √1960

Or u = 44.27 m/s

Thus, the initial velocity of the body is 44.27 m/s when thrown against the gravity to a height of 100 m.