Brakes, Exhaust and Idling: teacher key

Gas and Electric Cars, grade 5 edition, written for 5th grade. How gas cars and electric cars slow down, where a gas car sends its used gases, and what an electric motor does at a stop.

Read the book. Print this page for the key.

Questions and answers

1. What do brakes in a gas car turn motion energy into?
   • Heat (answer)
   • Fuel
   • Air
2. What can an electric car's motor act as when the car slows down?
   • A piston
   • A generator (answer)
   • A tailpipe
3. What sets how much power goes to an electric car's motor?
   • The controller (answer)
   • The muffler
   • The piston
4. Why does an electric car's motor not idle?
   • It stops when the car stops (answer)
   • It has a tailpipe
   • It burns fuel
5. What does regenerative braking reduce?
   • Wear on the brakes (answer)
   • The battery
   • The wheels

Words

• friction: rubbing
• generator: makes electricity
• transmission: power passer
• controller: power manager
• idle: run while stopped