Unit 6: Safety

UNIT 6: SAFETY

ESSENTIAL QUESTIONS• What is response time and what effects a person’s

response time?• How does speed effect a person’s response time?• What safety devices are on automobiles? Can these

safety devices actually increase the chance of injury?• How does Newton’s First Law relate to car collisions?• What are the optimal materials needed for seat belts?• How are airbags useful in collisions?• How can the movement of the head and neck be

limited in a collision?

DAY 1: RESPONSE TIME

• Learning Objectives:• Identify the parts of the process of stopping a car• Measure reaction time• Wire a series circuit

STARTER

• A lot of car accidents are due to the fact that the driver in a car could not respond in time to avoid being a statistic• Watch the following videos and discuss the

following with your group:• What is response time?• What factors affect how quickly someone is able to

respond in a car to avoid an accident?• How fast do you think your response time is?

• Time: 15 minutes

STARTER

STARTER (CONT’D)

ACTIVITY 1

• To stop a car, you must move your foot from the gas pedal to the brake pedal

• Cut out 2 squares: 1 for the brake, and one for the gas

• Time how long it takes for you to move your foot between the gas and the brake

• Repeat, but this time wait until your partner makes a noise to signal you to move from the brake to the gas

• Which is faster?• Why do you think this?• Time: 20 minutes

ACTIVITY 2

• Find your response time using an electric circuit• Set up an electric circuit as shown on pg. 81• Who in your group has the fastest response time?• What are some advantages to having a fast

response time?• Time: 20 minutes

ACTIVITY 3

• Find your response time using a ruler• How many cm does the ruler travel before you

catch it?• Try it with your eyes closed (your partner will give

you a signal they are dropping the ruler).• How does the response time change with your

eyes open vs. closed?• Time: 10 min

ACTIVITY 4

• Design an experiment to test response time• Be creative• Include the following:• Aim• Materials• Procedure• Expected outcomes

• Time: 20 minutes

CLOSING & HOMEWORK

• Physics to Go, pg. 84 #3, 4, 5• Reaction Time investigation plan

ACTIVITY 2: SPEED AND FOLLOWING DISTANCE

• Learning Objectives:• Define speed• Identify constant and changing speeds• Interpret distance-time and speed-time graphs• Contrast average and instantaneous speeds• Calculate the distance traveled at a constant speed

STARTER

• What is a safe following distance between you and the car in front of you?• What factors determine a safe following distance?• What happens if the safe following distance is not

obeyed? • Time: 10 minutes

ACTIVITY 1

• With your lab group, measure out a distance of 20m outside• Have one person walk the distance while you

time them• Have a second person job the distance while you

time them• Record your data and calculate their speeds• Speed = distance/time• Time: 25 minutes

ACTIVITY 2

• Graph the data you collected and extend your data points so they go for 100m• If the jogger started 30s after the walker, how

long would it take for the jogger to catch up to the walker?• How would you represent this on your graph?

• Time: 15 minutes

ACTIVITY 3

• A car is traveling at 60km/h (km/h m/s x0.278) leaves point A at 10:00am• A second car leaves point A at 10:05am and is

traveling at 70km/h• How long will it take the second car to reach the

first car?• After you solve this problem, create your own

word problem to solve.• Time: 20 minutes

ACTIVITY 4

• Create a poster with your group depicting the dangers of following a car too closely• Time: 15 minutes

CLOSING & HOMEWORK

• Physics to Go, pg. 91 #3, 6 (change miles to km… i.e 5 miles = 5km)• Graph• Poster

ACTIVITY 3: ACCIDENTS

• Learning Objectives: • Evaluate your own understandings of safety• Evaluate the safety features on selected vehicles • Identify safety features in selected vehicles• Identify safety features required for other modes of

transportation

STARTER

• Chances are you will not be able to avoid being in an accident at some time in the future.• How can you protect yourself from serious injury,

or even death, should an accident occur? This does not only have to do with being in a car, think of other places you can get into an accident.• What do you think is the greatest danger to you

or other people in the accident?• Time: 15 minutes

ACTIVITY 1

• Take the test on pg. 95 INDIVIDUALLY that will test your knowledge of automobile accidents• I will read out the correct answers when everyone

is finished so you can calculate your score• Time: 20 minutes

ACTIVITY 2

• How did you do?• Give yourself 2 points for every correct answer• Subtract 1 point for each incorrect answer

• 21-30 points: Expert Analyst• 14-20 points: Assistant Analyst• 9-13 points: Novice Analyst• 8 points or below: Myth Believer• Compare your results with the others in your group• Which question did most people answer incorrectly?

Why do you think that might be?• Time: 10 minutes

ACTIVITY 3

• We are going to survey different cars for various safety features• Each person needs to copy the table on pg. 97 to

fill out• You will survey 3 different cars and use a different

table for each car• We will go out to survey the cars when everyone

is ready• Which car was the safest?• Time: 45 minutes

CLOSING & HOMEWORK

• Serious injuries in an automobile accident have many causes. If there are no restraints or safety devices in a vehicle, or if the vehicle is not designed to absorb any of the energy in a collision, even a minor collision can cause serious injury• Which items from this survey in today’s activity

will be useful in helping you construct your safety system?• Physics to Go, pg. 98 #1 (use the list from today’s

activity), 2, 4

ACTIVITY 4 (60 MIN): LIFE BEFORE SEATBELTS

• Learning Objectives:• Understand Newton’s First Law of Motion• Understand the role of safety belts• Identify the three collisions in every accident

Have your homework out to be checked

STARTER

• In North America, there are laws that require automobile passengers to wear a seat belt.• Discuss in your group what the laws are in Congo

with regards to wearing a seat belt.• Do you think wearing should be a personal

choice?• What are two reasons why there should be seat

belt laws and two reasons why there shouldn’t be seat belt laws.• Time: 15 minutes

ACTIVITY 1

• Work in your lab groups to complete “For you to do”, steps 1-3 on pp. 99-100

• Record your observations and answer the questions as you go along

• From this simulation, can you think of a situation where a seat belt is not necessary? Explain.

• How does a seat belt help protect people in cars?• Hand in your observations and answers to these

questions when you are finished.• Materials on the back table• Time: 30 minutes

CLOSING & HOMEWORK

• Read “Physics Talk” and “For You to Read” on pp. 100-101• Physics to Go, pg. 102 #1, 3, 4• Stretching Exercises, pg. 104• Survey the members of your family to find out their

opinions about wearing seat belts

ACTIVITY 5: LIFE AFTER SEAT BELTS

• Learning Objectives:• Understand the role of safety belts• Compare the effectiveness of various wide and narrow

belts• Relate pressure, force, and area

Have your homework out to be checked

STARTER

• In collisions, you cannot brace yourself and prevent injuries. Your arms and legs are not strong enough to overcome the inertia during even a minor collision. Instead of thinking about stopping yourself when the car is going 50km/h, think about catching 10 bowling balls hurtling towards you at 50km/h. • Which do you think would be easier to do? Explain.

• Suppose you had to design seat belts for a racecar that can go 300km/h. How would they be different from the ones that are in passenger cars?• Time: 15 minutes

ACTIVITY 1

• Work in your lab groups to complete steps 1-3 from the “For you to do” on pg. 106• Materials for the seat belt are on the back lab

bench• Record your observations as you go, answer the

questions and hand in a copy when you finish• Take a picture of each of your “seat belts” and

email a copy to me (jbaranowsky@tasok.net)• Time: 45 minutes

ACTIVITY 2

• Watch the video presentation of the crash test dummy in a car collision.• In the collision, the car stops abruptly. What

happens to the driver?• What parts of the driver’s body are in the

greatest danger? Explain what you saw in terms of the law of inertia (Newton’s 1st Law)• Time: 10 minutes

ACTIVITY 3

• You may use this time to work on your chapter challenge with your group members• Note that there are 2 parts to this:• Displaying your model/prototype around the classroom• You will view other teams displays and write down questions

you have about them• Oral presentation

• This will be presented over 1 day on March 1

CLOSING & HOMEWORK

• Read “Physics Talk” and “For You to Read”, pp. 107-109• Physics to Go, pg. 109 #1, 2, 4 (Weight in

newtons = mass in kg x 10), 5

ACTIVITY 6: WHY AIR BAGS?

• Learning Objectives:• Model an automobile air bag• Relate pressure to force and area• Demonstrate that the force of an impact can be reduced

by spreading it out over a longer time

STARTER

STARTER

• Air bags do not take the place of seat belts, they are additional protection when used with seat belts• Why are air bags effective?• How does the air bag protect you?• Time: 15 minutes

ACTIVITY 1

• Any problems from last 2 lessons?• Homework checks from last 2 lessons• Time: 10 minutes

ACTIVITY 2

• Work through steps 1-4 of “For You to Do” on pg. 112• Your group will be assessed on how you perform

the activity as well as how you analyze the activity you complete• Time: 40 minutes

CLOSING & HOMEWORK

• Read “Physics Talk” pg. 113• Reflecting on the Activity and Challenge – how will

this activity help you with the chapter challenge?• Any questions regarding the chapter challenge?

(Due next Friday)• Summative assessment for the chapter will be a

written paper and you will have the break to complete it• Physics to Go, pg. 116 #1, 2, 3, 4, 6• For next class, read Activity 7 and bring in

supplies that your lab group will need (tape, rubber bands, string, wire, metal foil, etc.)

ACTIVITY 7: AUTOMATIC TRIGGERING DEVICES

• Learning Objectives:• Design a device that is capable of transmitting a digital

electrical signal when it is accelerated in a collision

STARTER

STARTER

• An air bag must inflate in a sudden crash, but must not inflate under normal stopping conditions.• How does an airbag “know” whether to inflate or

not?• Time: 15 minutes

ACTIVITY 1

• Get into your lab groups and work through the Inquiry Investigation on pg. 117

• The parameters are listed on pg. 118• You must devise a plan and test it using the

materials in class and the materials you brought in• Make changes to your design depending on how

your switch works• Video your design to show me in the next lesson• Type up your plan and any revisions you made to

your plan• Time: Remainder of period

HOMEWORK

• For you to read, pg. 118• Physics to Go, pg. 119 #1, 3, 4, 6