A car moves in a straight line so that its velocity decreases from 12 m/s at t=0 seconds to 3 m/s at t=6 seconds. Which statement describes the car’s average acceleration on 0≤t≤6?
(a) It is positive, about 1.5 m/s2, because aavg=612−3.
(b) It is zero because the car never reverses its direction of motion during the interval.
(c) It is negative because the velocity decreases from 12 m/s to 3 m/s.
(d) It is positive because all recorded velocities are directed forward.