Instantaneous velocity of (t^3)/3 when t= 2 ?

Question

and it's not 8/3..help!

Answer 1

If t^3 / 3 is the position function. Then its derivative would be the instanteous velocity.

s(t) = t^3 / 3

v(t) = t^2

v(2) = 4

Answer 2

dv/dt = t^2 which equals 4 when t = 2