Coronado High School, Henderson

SCIENCE 101 4.2.7 Explore: Driving Safety and Friction Coefficients
Exploration Physics Sem 1
Points Possible: 25
In this practice, you will apply what you have learned in the lesson. Answer the questions
below. Submit this to your teacher when you are done.
1. Use this article to answer questions about the braking systems used in cars. (9 points)

a. How do brake hydraulics work?. (3 point).
b. Describe disc brakes and the importance of friction in their use. (2 points)

c. Describe drum brakes and the importance of friction in their use. (2 points)

d. Explain how anti-lock brakes (ABS) work and why they are an important safety feature. (2
points)

2. Use this link to answer questions about ABS braking systems. (10 points)

a. Why is it easier to stop a car while the tires are rotating? (2 points)

b. Describe how the sensors on basic ABS braking systems work. (3 points)

c. Why is it easier to brake on dry roads, with or without antilock brakes? (2 points)

d. Conduct an internet search to learn what the most recent research indicates about these
questions: Do antilock brakes reduce the number of car crashes? Why or why not? Provide two
possible reasons. (3 points)

3. Use this link about vehicle stopping distance to answer the following questions. (6 points)

a. What two things determine the minimum stopping distance for a vehicle? (2 points)

b. What coefficient of friction is assumed for good tires and a good road surface? Use this
number in the stopping distance calculator. Then, plug in a speed of your choosing (for example,
35 mi/h), and find out what your stopping distance would be. Try it again with a much faster
speed. How did your stopping distance change? (4 points)