posted by Soly .
I have another question about my homework.
When a car stops, why should you have the engine running?
-Is it because you need to have friction between the car and the road inorder to make it run?
If it was a hybrid car, you wouldn't have to keep the engine running. It would stop automatically and start immedialely with an electric motor when the car has to start again.
With a gasoline-only car, you need to keep the engine running to be able to move away without wasting a lot of fuel and battery energy restarting the engine.
a story of how the pulley got its name