In a test run, a certain car accelerates uniformly from zero to 24.0 m/s in 2.95 s. (a) What is the magnitude of the car's acceleration? (b) How long does it take the car to change its speed from 10.0 m/s to 20.0 m/s? (c) Will doubling the time always double the change in speed? Why?

A. The thing that needs to be found is the magnitude of the car’s acceleration. We already know that

Acceleration = Velocity/Time

= 24/2.95 m/s^2

= 8.136 m/s^2

b. Initial velocity = 10 m/s

Final velocity = 20 m/s

Let us assume the time taken = t

Then

(20 - 10) / t = 8.136

8.136t = 10

t = 10/8.136

= 1.229 seconds

c. No, doubling the time will half the speed if all other conditions remain the same.