Question

A car traveling at a speed of 30.0 m/s encounters an emergency and comes to a complete stop in 7.5 seconds? What is the cars acceleration?

Answer 1

The acceleration is:
`4m/s^2`

Step-by-step explanation:

Given

`u = 30.0m/s` --- The initial velocity

`t = 7.5s` --- time

`v = 0m/s` -- The final velocity

Required

Determine the acceleration

To do this, we make use of the first equation of motion

`v = u - at`

We used negative because the car was coming to stop.

This gives:

`0 = 30 - 7.5 * a`

`0 = 30 - 7.5a`

Collect like terms

`7.5a = 30`

Solve for a

`a = (30)/(7.5)`

`a = 4m/s^2`