Chapter 6, Problem 4CQ

Two identical ice hockey pucks, labeled A and B, are sliding towards each other at speed v. Which one of the following statements is true concerning their momenta and kinetic energies?

(a) ${\stackrel{\to }{p}}_{\text{A}}={\stackrel{\to }{p}}_{\text{B}}\text{ and }K{E}_{\text{A}}\text{ = }K{E}_{\text{B}}$

(b) ${\stackrel{\to }{p}}_{\text{A}}=-{\stackrel{\to }{p}}_{\text{B}}\text{ and }K{E}_{\text{A}}\text{ = }-K{E}_{\text{B}}$

(c) ${\stackrel{\to }{p}}_{\text{A}}=-{\stackrel{\to }{p}}_{\text{B}}\text{ and }K{E}_{\text{A}}\text{ = }K{E}_{\text{B}}$

(d) ${\stackrel{\to }{p}}_{\text{A}}={\stackrel{\to }{p}}_{\text{B}}\text{ and }K{E}_{\text{A}}\text{ = }-K{E}_{\text{B}}$