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)`)

Explanation

`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