A body initially at rest is moving with uniform acceleration 'a'. It's velocity after n seconds is v. The displacement of the body in last 2 seconds is:

Options

A. `(2v(n-1))/(n)`
B. `(v(n-1))/(n)`
C. `(v(n+1))/(n)`
D. `(2v(n+1))/(n)`

Answer

a

Explanation

Here the displacement in last 2s `(1)/(2)an^(2)-(a)/(2)(n-2)^(2)`
`s=(a)/(2)[n^(2)-n^(2)-4+4n]`
=2a[n-1]
Also `a=("velocity")/("time")=(v)/(n)`
`:. S=(2v(n-1))/(n)`