(a) A world record was set for the men’s 100-m dash in the 2008 Olympic Games in Beijing by Usain Bolt of Jamaica. Bolt “coasted” across the finish line with a time of 9.69 s. If we assume that Bolt accelerated for 3.00 s to reach his maximum speed, and maintained that speed for the rest of the race, calculate his maximum speed and his acceleration. (b) During the same Olympics, Bolt also set the world record in the 200-m dash with a time of 19.30 s. Using the same assumptions as for the 100-m dash, what was his maximum speed for this race?
Step-by-step solution 40PE Step 1 of 6 The total distance traveled by the bolt is 100 m. If the distance traveled by the bolt while accelera ting is , then the remaining distance is that he traveled with the maximum velocity. Step 2 of 6 (a) The Bolt accelerates for 3.00 s, so the remaining 6.69 s he traveled with constant maximum velocity. Distance d travelled by the Bolt during acceleration is, Here, v is the final speed, u is the initial speed and t is the time interval for travelling distance d . Substitute 0 m/s for v and 3.00 s for . Step 3 of 6 The relation between the distance , time and the speed v of Bolt is, Substitute for and 6.69 s for . Substitute for d. Hence, the maximum velocity of Bolt is .