Question

A body travels 200cm in the first two second s and 220 cm in the next four second.the velocity at the end of seventh second from the will be

Answer 1

as S = ut + 1/2 at^2

200= u(2) + 1/2 x 2^2x a

100 = u + a ---- (1)

In next 4 sec,  420 = u (4) + 1/2 462 a

                           70 = u = 3a ------(2)

BY SOLVING 1 AND 2 WE GET

a = -15 and u = 115

by v = u = at

    v = 115-15  x 7 = 10 m/s

Answer 2

$\textbf{Answer is in Attachment !}$