Question

Two​ drivers, Alison and​ Kevin, are participating in a race. Beginning from a standing​ start, they each proceed with a constant acceleration. Alison covers the last one seventh 1 7 of the distance in 33 ​seconds, whereas Kevin covers the last one third 1 3 of the distance in 77 seconds. Who wins and by how much​ time?

Answer 1

Explanation:

Acceleration is the rate of change of velocity. When acceleration is high, it means that the velocity is not changing. Since they ran at a constant acceleration, it mean that their velocities didn't change throughout.

If Alison covers the last one seventh of the distance in 33 ​seconds, it means that the distance covered in 33 seconds is

1/7 = 0.14

Velocity = distance/time

Velocity of Alison = 0.14/33 = 0.004242

If Kevin covers the last one third of the distance in 77 seconds, it means that the distance covered in 77 seconds is

1/3 = 0.33

Velocity of kelvin = 0.33/77 = 0.004286 m/s

We can see that Kelvin has a greater speed. So kelvin had covered Alison's, distance, the time he would have spent is

Time = distance/velocity

Time = 0.14/0.004286 = 32.66

The time difference would have been 33 - 32.66 = 0.34 seconds

Kelvin won by 0.34 seconds