A new train travels along a straightline track Data obtained

A new train travels along a straight-line track. Data obtained from the speedometer indicate that the velocity of the train at any time t can be described by the velocity function, v(t) = 8t (0< t< 30). Find position function of train. Find position after 3 seconds. (Hint: Train starts from the beginning of track, so t= 0.

v = 8t dx/dt = 8t x = 4t^2 => postion function after 3s pos, x = 36