<p>Does he know any basic calculus now? Once he’s learned the mechanics portion of AP Physics B, the mechanics portion of AP Physics C doesn’t really add THAT much new material, whereas the E&M part is probably too hard to do simultaneously. The basic problem solving notions are the same. The new stuff is basically some simple calculus and more depth on rotational mechanics. Also, at most schools Physics C Mechanics is taught simultaneously with Calculus, so the amount calculus needed isn’t huge. </p>
<p>If he uses Giancolli for Physics B, the same author has another book suitable for Physics C (I think it’s called Physics for Scientists and Engineers). I mention this because many sections in the two texts are word for word identical, so it’s really easy to figure out what material in Physics C isn’t in Physics B. </p>
<p>I think Physics C Mechanics is a good prerequisite for Physics C E&M because the latter requires more calculus, and having done some calculus in Mechanics, which is easier, would probably help a lot. </p>
<p>If he has time now, and you can get a tutor, It might not be that hard to have someone tutor him so that he could take both Physics B and Physics C Mechanics this May. They are usually offered at the same time, so he’d have to take the Physics C exam during the conflict period. Still, it seems easier than taking the Physics C Mechanics class which has so much of the same material yet will require redundant homeworks that may start to seem like busywork when he’s already so busy.</p>
<p>I agree with QM too though. Vector calculus was made for E&M and teaching it without it just makes it harder. Physics C might give him the edge to get into an honors physics class in college where they teach E&M that assumes fluency with MVCalc. Then it gets really cool!</p>