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

Answer:

-35 $m/s^2$

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 $m/s^2$.