posted by KJ .
A speedboat starts from rest and accelerates at +2.01 m/s2 for 7.05 s. At the end of this time, the boat continues for an additional 6.15 s with an acceleration of +0.518 m/s2. Following this, the boat accelerates at -1.49 m/s2 for 8.50 s.
(a) What is the velocity of the boat at t = 21.7 s?
(b) Find the total displacement of the boat.
find the initial and final velocity for each time period.
then each vf becomes vi for the next period.
For total displacment find d for each period, and add them
d=vi*t+1/2 a t^2