Question

The first 20 meters of a 100-meter dash are covered in 3.5 seconds by a sprinter who starts from rest and accelerates with a constant acceleration. The remaining 80 meters are run with the same velocity the sprinter had after 3.5 seconds.

A. Determine the sprinter's constant acceleration during the first 3.5 seconds.

B. Determine the sprinter's velocity after 3.5 seconds have elapsed

C. Determine the total time needed to run the full 100 meters.​

Answer 1

See below

Step-by-step explanation:

A ) distance = 1/2 a t^2 <==== when starting from rest

20 = 1/2 (a) (3.5^2) shows a = 3.27 m/s^2

B) Velocity(at 3.5 s) = a t = 3.27 * 3.5 = 11.42 m/s

C) 3.5 seconds + 80 m / 11.42 m/s = 10.5 s