Question

4.
A ball is dropped from a bridge of 122.5 metre
above a river. After the ball has been falling for
two seconds, a second ball is thrown straight down
after it. Initial velocity of second ball so that both
hit the water at the same time is
(1) 49 m/s
(2) 55.5 m/s
(3) 26.1 m/s
(4) 9.8 m/s
i know the answer
I want the explanation
plz help​

Answer 1

Answer:

26.133 m/s

Explanation:

Time taken by first ball to hit water can be found as

s= ut + ½ gt2

122.5 = ½ * 9.8 * t2

t2= 25

t =5

Now the next ball must cover this distance in 3 s to hit water at same time.

122.5 = 3 u + ½ * 9.8 * 32

122.5 = 3u + 44.1

3u = 78.4

u= 26.133 m/s

So option c is correct.

Plz mark as brain list.