In one of the conceptual physics textbooks, the question asked was
whether there was a greater consumption of gas in a car while the engine
was running if the car lights were left on. As obvious as the answer
seemed, I responded, yes it would. The energy had to come from
somewhere. But one of my students reminded me that the alternator ran
all the same whether the lights were on or not; so the overall gas
consumption stayed the same; in his opinion, it did not make any
difference. What do you think?
- Abby