Question

A sprinter is practicing her starts on a 100 m long straight track. From rest, she starts running with an acceleration of 4.2 m/s2 until she reaches her top speed of 10 m/s. Once up to speed, she immediately relaxes, decelerating slowly at a rate of -1.3 m/s2 until she comes to a stop.

(a) Draw the motion diagram (including velocity vectors) for the sprinter. Please label her starting point and end point, and where she reaches her maximum speed.

(b) Draw her acceleration vector at a time when she is slowing down.

(c) Draw graphs of position, velocity, and acceleration of the sprinter as functions of time labeled with appropriate units. (You do not need to include numbers on the graph, but please clearly show the points at which she begins to decelerate, and when she comes to a stop again. Also clearly differentiate between what’s a straight line, what’s curved, what’s flat, etc.)

Answer 1