Now we want to analyze a physical system comprised of two particles. Look at the pair-wise potential

energy. Suppose r is equal to 1.2s.

a) Suppose the particles are momentarily at rest at r = 1.2s (like a ball at the top of its trajectory

when thrown straight up). What can you say about the total energy, Etot, and the subsequent

motion of the two particles?

b) Now suppose at the instant the particles have the separation 1.2s they have total KE equal to

0.1e. What can you say about the total energy, Etot, and the subsequent motion of the two

particles