Question

(99 POINTS) While driving her new Camaro at 20.0 m/s down a four-lane highway, Jessica comes up behind a slow-moving dump truck and decides to pass in the left-hand lane. If Jessica can accelerate at a rate of 5.0 m/s2, how long will it take for her to reach a speed of 30.0 m/s?

Answer 1

2 seconds

Step-by-step explanation:

There is a velocity change of 10.0 m/s.

a = (velocity change)/(time required)

From this a = 5.0 m/s^2, so

time = (10.0 m/s)/(5.0 m/s^2)

= 2.0 seconds

Answer 2

To go from 20.0 to 30.0 m/s, that is a velocity change of 10.0 m/s.

From the definition of acceleration,

a = (velocity change)/(time required)

In this case you know that a = 5.0 m/s^2, so

time = (10.0 m/s)/(5.0 m/s^2)

= 2.0 seconds