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

Answer:

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

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

$a = \frac{30}{7.5}$

$a = 4m/s^2$