Question

When Marie sees the red traffic light, Marie brakes to a halt from a speed of 70 m/s in just 2 seconds. What is her deceleration?

Answer 1

-35
`m/s^2`

Step-by-step explanation:

Deceleration is the complete opposite of acceleration and is calculated by adding a negative sign to the formula for finding acceleration.

Since acceleration is calculated by diving the change in velocity with time, deceleration will become:

Deceleration = -Δv/t, where Δv = change in velocity and t = time

In this case, Δv = 70 m/s and t = 2 s, hence;

Deceleration = -70/2 = -35
`m/s^2`

The deceleration is 35
`m/s^2`.