A drag racer starting from rest accelerates in a straight line at a constant rate of \(5.5 \mathrm{~m} / \mathrm{s}^{2}\) for \(6.0 \mathrm{~s}\).

(a) What is the racer's velocity at the end of this time?

(b) If a parachute deployed at this time causes the racer to slow down uniformly at a rate of \(2.4 \mathrm{~m} / \mathrm{s}^{2}\), how long will the racer take to come to a stop?

THINKING IT THROUGH. The racer first speeds up and then slows down, so close attention must be given to the directional signs of the vector quantities. Choose a coordinate system with the positive direction in the direction of the initial velocity. (Draw a sketch of the situation for yourself.) The answers can then be found by using the appropriate equations. Note that there are two different parts to the motion, with two different accelerations. Let's distinguish these phases with subscripts of 1 and 2.