A Car of Mass M, Traveling with a Velocity V

Multiple Choice

A car of mass M, traveling with a velocity V, strikes a parked station wagon, whose mass is 2M. The bumpers lock together in this head-on inelastic collision. What fraction of the initial kinetic energy is lost in this collision?

A) 1/4
B) 1/3
C) 2/3
D) 1/2
E) 1/9