## Braking

**Approach**

**Approach**

**Solution**

**Solution**

## Part B

## Approach

The average speed under constant acceleration is (vf + v0)/2. (You can also use stopping distance divided by the time it takes to stop.)

## Solution

vave = 19.72/2 m/s = 9.86 m/s

## Part C

## Approach

Since the braking force results in a constant deceleration, the time it takes to stop can be determined using v = v0 + at.

## Solution

Time: t=(v−v0)a=−1972ms−65ms2=303s