Question

A particle starts from rest with uniform acceleration a. its velocity after n seconds is v. the displacement of the particle in last two seconds is:

Answer 1

calculate s1 = u(t-2) + 1/2a(t-2)^2 and s2 = ut+1/2at^2 (Given u =0)


subtract the two ie s2-s1 = 1/2at^2 - 1/2a(t-2)^2
 = 1/2a(t^2 - t^2-4+2t) = a(t-2)

displacement  = a(t-2)