Hybrid cars.

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CORRECTION:

In our Watersheds issue, student levels C, D, and E incorrectly gave the area of the Pacific Ocean as 64 million square feet. It should have read 64 millon square miles. We apologize for the oversight.

Why Hybrid?

There are two incentives for developing hybrid vehicles. Oil is expensive and the supply of oil is subject to political pressures and disruptions. Hybrid cars reduce reliance on oil by substituting other sources of energy. The second motivation is to reduce the pollution produced by gas-burning vehicles.

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DID YOU KNOW??

Over 2 million hybrid cars have been purchased in the United States.

Two Are Better Than One

The combination of an electric engine and the traditional internal combustion engine reduces the demand for gas. In some hybrids, the gas engine is used primarily to charge the electric motor, which, in turn, drives the car. In other hybrids, the two engines take turns depending on the speed of the car.

Electric motors are not free of problems, however. Batteries eventually lose their charge. They can be plugged into electrical receptacles to recharge, but a need to plug in seriously limits the distance that can be traveled without stopping to recharge. Regenerative braking solves that problem by recharging as the car is run. And it requires no extra fuel!

And Cleaner, Too

Electrical engines produce no exhaust and consequently, cut down on the amount of pollutants added to the air by the use of the vehicle. Victor Wouk developed a prototype of a hybrid car in the late 1960s. By 1970, California had passed the Clean Air Act, which required a reduction in automobile emissions of 95%. Wouk explained in an interview how the number 95% had been determined. When he was in college in Southern California in the 1930s, Catalina Island had been visible from the area on most days. By 1970, it could rarely be seen due to the smog. The 95% reduction in automobile emissions was thought to be the amount needed for Catalina Island to become visible again from the Southern California coast.

Put It All Together

The two engines used by many hybrid cars can be connected in either a serial or parallel arrangement. The concepts of serial and parallel connections are important in science for many uses. Electronic circuits controlling everything from strings of lights to railroad trains can be connected in one of these two ways. These concepts are also important in understanding the circulatory system of our bodies. Learning about the design of hybrid cars can help your students to form a concrete visual understanding of parallel and serial connections, which will help them in their future science studies.

Initiating Questions Levels Pre-A-B

1. What can we do to use less gas?

2. What can we do to keep our air clean?

Follow-up Questions Levels Pre-A-B

3. How do hybrid cars use less gas?

4. Why are hybrid cars cleaner?

Level Pre-A

Main Concept: Hybrid cars save gas by using electricity, too. Electricity helps keep the air clean.

Picture Activity

Ask students why using too much gas is a problem. Discuss how expensive gas can be. Ask students if they have noticed the smell of gas at a gas station. Is that the air we want to breathe?

Vocabulary

Ask students what else can be a hybrid. Suggest hybrid plants such as fruits that are a combination of two kinds of fruit (e.g. pluots: half plum, half apricot).

Weekly Lab

This is an activity that should convince students that working cooperatively lightens the load: two types of engines are better than one.

Math

Think of other activities that require 3 or 4 steps. What happens if we do the steps out of order?

Storytelling

Our choices affect other people. The car we drive can make the air cleaner or dirtier for others. Think of choices that students can make that affect other people.

DID YOU KNOW??

The use of an electric motor in hybrid cars also reduces traffic noise.

Challenge

Answer: The first letters of each word spell HYBRID.

Bringing It Home

Answer: gas powered lawn mower; electric lamp Have students think of other common objects that either run on gas or work with electricity. Examples are a gas-powered hedge trimmer and an electric (battery-powered) flashlight.

Level A

Main Concept: (Please see Level Pre-A). Hybrid cars have a gas motor and an electric motor.

Vocabulary

(Please see Level Pre-A.)

Weekly Lab

CAUTION! ADULT SUPERVISION REQUIRED. Please provide adequate adult supervision for this activity to guard against accidental injuries. This activity will give the students a concrete visual understanding of how the two engines can be combined. Emphasize that in the serial arrangement (one student pushing the other), only one motor actually drives the car while the second motor helps. In the parallel arrangement, both motors drive the car at the same time.

Math

Answers: 4 hybrid cars + 3 non-hybrid cars = 7 cars in all

Bonus Answer: 1 more hybrid car than non-hybrids

Writing in Science

Students can explain that the gas engine needs less fuel because it gets help from the electric engine. They can also notice that the electric engine is clean so there is less pollution from the car.

Challenge

(See Word Search solution, below.)

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Bringing It Home

Talk about what kind of car each student would buy. Why did they make that choice?

Level B

Main Concept: (Please see Level A.) In hybrid cars the two motors can be used in different ways. In some hybrids the electric motor drives the car and the gas motor helps. In other hybrids the two motors can work at the same time or take turns. Hybrids use less gas and help keep our air cleaner.

Vocabulary

Answers: energy; Hybrid; electricity; cleaner

Weekly Lab

CAUTION! Please read SAFETY STICKY NOTE to the right. The pieces of tissue paper will be pulled toward the balloon and the comb. Both objects acquire static electricity from the friction energy created when the objects are rubbed on the student's hair (or wool scarf). That electricity then pulls the tissue paper.

Math

Answers: The hybrid can go 40 km on 2 liters of gas; the ordinary car can go 20 km on 2 liters of gas; the hybrid can go 20 km farther than the ordinary car on 2 liters of gas.

Writing in Science

Students can explain that the static electricity from the friction of rubbing attracts the tissue paper.

Challenge

Students should identify the cleaner car (without exhaust fumes) and the one with the better gas mileage (more miles per gallon) as the hybrids.

Puzzle

Answers: electricity; energy; motor; clean A good color for a hybrid car is green.

Initiating Questions Level C

1. Why is it a problem to drive cars that use only gas?

2. If you had two engines to drive a car, how might you put them together?

Follow-up Questions Level C

3. How do hybrid cars help our environment?

4. What is an important problem for electric engines?

DID YOU KNOW??

The first hybrid car was developed in 1900 by Ferdinand Porshe. There were hybrid buses in England one year later and hybrid cars available in Canada in 1915. The first hybrid SUV was developed and made available in 2005.

Level C

Main Concept: (Please see Level B.) Hybrid cars help reduce pollution. But electric batteries need to be recharged after only 100-200 miles, which is one reason electric cars can be problematic.

Vocabulary

Answers: 1) engine; 2) battery; 3) Hybrid; 4) electricity; 5) pollutes

Weekly Lab

CAUTION! Please read SAFETY STICKY NOTE to the left. This should be an impressive activity. The water will noticeably bend toward the balloon or comb.

Math

Answers: The hybrid car can drive 90 km on 5 liters of gas; the ordinary car can drive 50 km on 5 liters of gas; the hybrid car can drive 8 km more than the ordinary car on 1 liter of gas.

Writing in Science

The static electricity attracts the molecules in the stream of water.

Challenge

Also, students can specifically try to make rhyming words such as side, hide and bride as an additional challenge.

FYI-Further Your Interests

Answer: All of the objects shown are available in hybrid versions! Students should circle all of the pictures.

Initiating Questions Levels D-E

1. What would be the benefits of using electricity to power a car?

2. What are some problems of using electricity?

3. How might you connect two engines to drive a car?

Follow-up Questions Level D-E

4. What is the difference between motors connected in serial and in parallel?

5. What is meant by "conservation of energy?"

6. How do some hybrid cars benefit from the principle of conserving energy?

Level D

Main Concept: (Please see Level C.) Hybrid cars use two engines which can be connected in serial, meaning that one assists the other, or in parallel, which means that both engines work together to drive the car. A moving car is using kinetic energy. Using the principle of conservation of energy, some hybrids use the resulting heat energy from the friction of the brakes to recharge the battery.

SAFETY STICKY NOTE

For the lab activities for Levels C, D and E, students will be generating static electricity by rubbing objects against their hair or wool scarf. For the sake of hygiene concerns in the classroom, please use discretion in how you direct students to do the activity. Avoid situations where a single shared object will be rubbed on the hair of multiple students. You may elect to rub the items against a wool scarf which should also work well for generating static electricity. Please provide adult supervision for these labs.

Vocabulary

Answers: 1) hybrid; 2) pollutes; 3) energy, recharge; 4) kinetic; 5) electricity, battery

Weekly Lab

CAUTION! Please read SAFETY STICKY NOTE on page 3 of the TEACHING NOTES. This is a very impressive activity. The foil ball will noticeably move towards the charged object.

Math Answers: 36 mpg X 1.6 km per mile = 57.6 km per gallon; 57.6 km per gallon / 3.8 liters per gallon = 15.2 km/liter

Bonus Answer: 20 km per liter X 0.6 = 12 miles per liter; 12 miles per liter X (1 liter / .26 gallons) = 12 / .26 = 46 miles per gallon (rounded)

Writing in Science

Students should be aware of rising gas prices and may be aware of difficulties in obtaining adequate oil. Encourage the students to think about the effects of pollution on health, noise, and the environment.

Challenge

Answers: Electricity can be created by the following: dam, wind farm solar panels.

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Where in the World?

(See map solution, above.)

DID YOU KNOW??

Hybrid vehicles are allowed to park for free in some parts of Israel and New Zealand.

Level E

Main Concept: (Please see Level D.) Some hybrid cars use the principle of conservation of energy to recharge the battery in a process called regenerative braking.

Vocabulary

Answers: 1) hybrid; 2) pressure; 3) electricity; 4) energy; 5) pollute; 6) recharge; 7) friction; 8) kinetic

Talk to students about how words can take on different connotations depending on the context.

Weekly Lab

CAUTION! Please read SAFETY STICKY NOTE on page 3 of the TEACHING NOTES. Additionally, students should be closely supervised while handling light bulbs to avoid injuries. This is a terrific activity. Students will be able to hear a slight crackling sound as the bulb takes on a charge from the static electricity. Be sure to use a darkened room so students can see the bulb glow from the electricity they create from the friction.

Math

Answers: CIRCUIT 1: 7A, 7A; CIRCUIT 2: 25A; CIRCUIT 3: 60A; CIRCUIT 4: 6A, 6A, 6A This exercise may be challenging but will help your students to strengthen logical thinking abilities.

Writing in Science

Students should be able to think beyond the expense of gas and discuss political problems in obtaining adequate oil. Guide them to reflect on the effects of pollution in our air.

Challenge

Answers: 1) Serial In-Serial Out; 2) Parallel In-Parallel Out; 3) Serial In-Parallel Out; 4) Parallel In-Serial Out

FYI-Further Your Interests

Answers: 1) serial; 2) parallel

Math

Count the cars.

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How many cars are hybrids?

How many cars are not hybrids?

How many cars in all?

BONUS!

Do you know how many more hybrid cars than other cars?

Writing in Science

Hybrid cars have two motors, Why is that better than one motor? Write a complete sentence.

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Challenge

Find the words from the list. Circle the words,

WORD LIST

GAS ENERGY HYBRID ELECTRICITY MOTOR CLEAN

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Bringing It Home

Circle the car that is a hybrid car. Color the picture.

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"Do you like science or art better?"

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"I like both. Besides, artists actually use science for their work."

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"Our next issue will teach us all about the connections between science and art!"

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Weekly Resources

Helpful Sources for Planning Your Science Weekly Classroom Activities

Recommended Resources

* Boschert, Sherry. Plug-in Hybrids: The Cars that Will Recharge America. Gabriola Island, BC: New Society Publishers, 2006.

* Miller, Debra A. The Green Movement. Detroit, Michigan: Greenhaven Press, 2010

Internet Resources

How Stuff Works http://www.howstuffworks.com/hybrid-car.htm

The Atlantic http://www.theatlantic.com/technology/archive/2011/06/infographic.how-does-a- hybrid-car-engine-actually-work/241021/

Consumer Reports

http://www.consumerreports.org/cro/cars/new-cars/news/2008/04/ guide-to-hybrid.cars/-overview/guide-to-hybrid-cars-ov.htm

Fuel Economy http://www.fueleconomy.gov/feg/hybridtech.shtml

Earth's Friends

http://www.earthsfriends.com/how-do.hybrid-cars-work

Hybrid Cars

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Most cars use gas for energy (en-er-gy). Hybrid (Hy-brid) cars use gas and electricity (e-lec-tric-i-ty). Most cars have a gas motor (mo-tor), Hybrid cars have a gas motor and an electric (e-lec-tric) motor. Hybrid cars use less gas. Hybrid cars help keep our air clean.

New Words

gas energy Hybrid electricity motor electric clean

Vocabulary

Write the word Hybrid in each sentence.

cars use gas and electricity.

cars use less gas.

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cars have a gas motor and an electric motor.

cars are cleaner.

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Weekly Lab

What is so good about hybrid cars?

You need: a partner, a wagon

Step 1: One child sits in the wagon,

Step 2: Push the wagon by yourself.

Step 3: Push the wagon with a partner. Your partner can push you from behind.

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Which was easier?

[] by yourself [] with a partner

Step 4: Pull the wagon by yourself.

Step 5: Pull the wagon with a partner. Pull the wagon together.

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Which was easier?

[] by yourself [] with a partner

Science says ...

The electric motor and the gas motorwork together.