Physics problem in Einstein's Relativity. It is a good practice problem for Honors and AP Physics 2 students. The problem is the following:One fascinating topic in physics is Einstein’s Relativity. Although humans still cannot travel close to the speed of light, scientists can estimate the mass expansion and the time dilation of particles moving in particle accelerators, in the decay of fast moving muons, and in many other situations. In the plot of the 1968 movie the Planet of the Apes with Cha