So what's wrong with that? Why is the explanation in the Physics book any better?
"So what's wrong with that? Why is the explanation in the Physics book any better?"
Because when asking proximate questions, proximate answers are more valuable than ultimate answers.
Answering any question about nature with 'God-did-it' tells us nothing about the physical processes which lead up to those questions. It tells us nothing to use 'God-did-it' as an explanation for why a rock tumbles down a hillside and eventually stops. If we ignore God for a moment and investigate non-supernatural causes we see that gravity, friction, potential energy and kinetic energy can give us a much more precise answer. If you want you can claim that God created those forces, but you do not have to claim he/she/it personally sent the rock down, determined its speed and stopped it at the bottom.