A grap?h? of? (?t) is shown for a world-class track sprinter in a 100-m race. (See Figure 2.67). (a) What is his average velocity for the first 4 s? (b) What is his instantaneous velo ? city a? = 5 s ? (c) What is his average acceleration between 0 and 4 s? (d) What is his time for the race?

Step-by-step solution 65PE Step 1 of 7 The average velocity is defined as the total dis covered by the body divided by the total ti it takes to cover that distance. Step 2 of 7 The time in seconds and corresponding velocity in m/s at that time tabulated from the graph is below, time (s ) v (m/s) 0 0 1 3 2 6 3 9 4 12 5 12 6 12 7 12 8 12 9 12 10 12 (a) Total displacement of the sprinter for first 4 s is the area under Velocity vs. Time graph for first 4 s. Step 3 of 7 The area under graph is the area of right angle triangle ABC. So, the displacement is, Substitute, 12 m/s for B C and 4 s for A C, The average velocity of the sprinter for first 4 s is, Substitute, 24 m for d and 4.0 s for t. Step 4 of 7 (b) The instantaneous velocity of the track sprinter at 5 s from the graph is