Physics Question

With respect to “Below Average” (Feb. 25), we have a problem. Please do not throw any hollow rocks at my windows. The reason the window did not break was that the tennis ball was resilient, and while deforming when it hit the window it absorbed some of the kinetic energy of impact and spread the load over a larger area. Maybe the test makers should be graded?

SANDY FRIEDFELD

Rancho Palos Verdes