Problem 58P

IP You are driving through town at 16 m/s when suddenly a car backs out of a driveway in front of you. You apply the brakes and begin decelerating at 3.2 m/s2, (a) How much time does it take to stop? (b) After braking half the time found in part (a), is your speed 8.0 m/s, greater than 8.0 m/s, or less than 8.0 m/s? Support your answer with a calculation, (c) If the car backing out was initially 55 m in front of you, what is the maximum reaction time you can have before hitting the brakes and still avoid hitting the car?

Solution 58P

Part (a)

Step 1 of 6:

We are traveling in a car with a particular speed and suddenly an another car backs out of a driveway. We apply the brakes and the car starts decelerating. We are going to find the time taken for us to stop completely.

The initial speed vo = 16 m/s

The final speed v = 0

The acceleration a = -3.2 m/s2 (deceleration)