Elastic collision resulting in both balls at rest · CAP 2004 #Q10
Physics · mechanics
Problem
Students claim that in a lab experiment they witnessed a head-on elastic collision between two balls on a horizontal surface which resulted in the balls being both at rest. No external horizontal force was acting at any time on the masses. Which of these comments is the most appropriate about this process?
(a) Initial speeds and masses must have been different;
(b) initial speeds and masses must have been identical;
(c) initial speeds, but not necessarily masses, were identical;
(d) the process cannot have occurred as claimed.