Question

A particle starts from rest with uniform acceleration and is velocity after `n` seconds `v`. The displacement of the body in last two seconds is.
A. 2v(n - 1)/n
B. v(n - 1)/n
C. v(n + 1)/n
D. 2v(n + 1)/n

Answer 1

Correct Answer - A
Here, `a = v - u/t =v - 0/n = v/n`
Displacement in last 2 s
`S_n - S_n-2 = 1/2 an^(2) - 1/2 a(n - 2)^(2)`
`2a(n - 1) = (2 v)/(n (n - 1)) = (2v(n - 1))/n`