AAMC FL Sample Test: Incorrect information in explanation?

[ZDMaestro]

---

Members don't see this ad.

So... The answer is right, but I think their explanation has wrong information. Humor me.

The chemistry/physics section, question 29. "Since the potential energy is proportional to the square of the distance between two oppositely charged particles..." This is incorrect, right? It depends on the distance, but not the square of that distance.

Please tell me if I'm wrong!

 

[RaspberrySlushy]

Yes I think you are correct. That stood out to me too. Force is inversely proportional to square of distance, electric potential energy is just inv. Prop. to distance.

 

[StudyLater]

Makes you nervous about how they're actually grading the real thing, huh?

 

[ZDMaestro]

Seriously. Makes me really uncomfortable...

I can't remember the details now, but there was one question on the real MCAT (June) that I had a really big problem with... Unfortunately, I cannot remember anything about it other than I had a problem with it and thought it should probably be contested. Sigh.

 

[Altius Premier Tutor]

Yes I think you are correct. That stood out to me too. Force is inversely proportional to square of distance, electric potential energy is just inv. Prop. to distance.

Yes. This is one of a few errata in AAMC1. Potential Energy (PE) for a point-charge system [different from a constant electric field] is: PE = kqq/r ; but don't forget that for the strength of the electric field: E = kq/r^2. Everyone needs to know the relationships for constant E-fields as well: PE = qEd and E = F/q or V/d.