Question

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

Answer 1

the distance travelled by the particle in the last two seconds will be = distance travelled by particle in nth second - distance travelled by particle in (n-2)th secondso,s = (1/2)an2 - (1/2)a.(n-2)2= (1/2)a.[n2 - n2 +4n - 4] = (a/2).[4n - 4]so,s = (2n-2).a = 2a.(n-1) ............................(1)now,velocity, v = acceleration x timev = a x n ora = v/n ..........................(2)so, the displacement in the last two seconds will bes = 2(v/n).(n-1)

Answer 2

hope this is beneficial !