In the print version of the article in the March issue by Carl Mungan, Fig. 2 was mistakenly reprinted in place of Fig. 4 on page 182. Below is the correct Fig. 4.

AAPT members receive access to The Physics Teacher and the American Journal of Physics as a member benefit. To learn more about this member benefit and becoming an AAPT member, visit the Joining AAPT page.