A locomotive of mass 21X10^3 kg travelling at 2.0m/s runs into an identical stationary locomotive.
a) if the collision is perfectly inelastic, and the two trains lock together, what is their speed after the collision?
b) if the collision is perfectly inelastic, what fraction of the energy is lost after the collision?
c) if the collision is perfectly elastic, find the motion of the locomotives after the collision.
d) if the collision is perfectly elastic and lasts for 1.5s, find the average force exerted on the stationary locomotive during the collision.