WeBWorK Problems

Answer error?: Library/Rochester/setVectorCalculus3/ur_vc_13_1.pg

Answer error?: Library/Rochester/setVectorCalculus3/ur_vc_13_1.pg

by Murray Eisenberg -
Number of replies: 2
I think the answers given
 for Library/Rochester/setVectorCalculus3/ur_vc_13_1.pg
are wrong. For the question's parameters a, b, c, d = a*c, the supplied answers are b and b/c for parts (a) and (b), respectively. I obtain, instead, b*c and a*b*c.

Would you kindly take a look at that as well as my attached solution?

I think my algebra is OK, but perhaps I'm misreading something.
In reply to Murray Eisenberg

Re: Answer error?: Library/Rochester/setVectorCalculus3/ur_vc_13_1.pg

by Lars Jensen -
Hi Murray,

The problem looks OK, but ther's an error in the definition of your force field. Your definition of the force field in part A is equivalent to F = (k/r) n, where n is your outward pointing unit vector. This field is inverse in r, not inverse-square in r. In your notation, your definition should be F = (k/r^2) n. Similarly for part B.

Lars.