Elbert Derick in his letter published Nov. 5 put acceleration due to gravity at 64 feet-per-second-per second. I don’t know if he got that figure on his own or from the test question, but the figure is incorrect.

According to the physics class I took oh-so-many years ago, the figure is 32 feet, or about 9.8 meters per second squared.

Marc Breton, Lewiston