A ball dropped from the 9th story of a multi - storeyed building reaches the ground in 3 second. In the first second of its free fall, it passes through storeys, where n is equal to ( Take g=10 m s^(-2))

A ball dropped from the 9th story of a multi - storeyed building reach

1.	A ball dropped from the 9th story of a multi - storeyed building reaches the ground in 3 second. In the first second of its free fall, it passes through storeys, where n is equal to ( Take g=10 m s^(-2))
Answer» Solution :`9y =1/2 XX 10 xx 3 xx 3 or y=5m` Again, `n xx 5 =1/2 xx 10 xx 1 xx 1 =5` or n=1