A cyclist starts from rest at point A, accelerates along a straight, level road to a speed of 8 m/s in 4 s, maintains that speed for the next 6 s, and then applies the brakes uniformly to come to rest at point B in 3 s. Treat the cyclist and bicycle as a single point object.
(a) Calculate the magnitude and sign (positive taken as forward, negative as backward) of the average acceleration during each of the three time intervals described.
(b) On a single qualitative time axis, sketch the acceleration as a function of time for the entire trip from A to B. Clearly label the values obtained in part (a).
(c) Identify the specific instants or intervals, if any, during which the cyclist’s acceleration is zero even though the cyclist is still moving. Justify your answer.