Physics problem help?

Question

A speedboat start from rest and acceleration at + 2.01 m/s^2 for 7.00 s. At the end of this time the boat continues for an additional 6.00 s with an acceleration of +0.518 m/s^2. Following this, the boat accelerates at -1.49m/s^2 for 8.00s What is the velocity of the boat at t = 21.0 s? (b) Find the displacement of the boat.

Answer 1

If acceleration = delta velocty/time and velocity = displacement/time.

First leg:

2.01m/s^2 (7s)= 14.07 m/s velocity

14.07 m/s (7 s) = 98.49 m

Second leg

.518 m/s^2 (6 s) = 3.108 m/s velocity

3.106 m/s (6 s) = 18.648 m distance travelled

Third leg

-1.49 m/s^2 (8s) = -11.92 m/s relative to the starting point in the leg.

-11.92 m/s (8s) = -95.36 m again relative to the starting point in the leg.

The definition of displacement is the part that's s******g me up.  Is displacement defined as the total distance travelled or the distance from the relative starting point?  Your textbook definition of displacement will give you your final answer.