# physics

posted by
**randy** on
.

A speedboat starts from rest and accelerates at +1.68 m/s2 for 5.43 s. At the end of this time, the boat continues for an additional 8.16 s with an acceleration of +0.475 m/s2. Following this, the boat accelerates at -0.866 m/s2 for 7.54 s. (a) What is the velocity of the boat at t = 21.13 s? (b) Find the total displacement of the boat.