In `n^(th)` second of the motion, the distance moved by the body is three times the distance moved in the previous second. The motion is uniformly accelerated and the initial velocity was zero. Find n.

Answer

2

Explanation

`S_(n)=u+(1)/(2)a(2n-1)`
`S_(n-1)=u+(1)/(2)a(2(n-1)-1)`
`S_(n-3)S_(n-1)implies(1)/(2)a(2n-1)=3xx(1)/(2)a(2n-3)`
`2n-1=6n-9`
`4n=8`
n=2