Question

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?
m/s
(b) Find the total displacement of the boat.

Answer 1

find the initial and final velocity for each time period.
vf=vi+at

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