Derive a general formula for the energy lost in the inelastic collision. Calculate the energy lost and the fraction of the energy lost in the collision of the mass m = 1 kg moving with the speed v = 2 m/s and the mass m = 2 kg moving with the speed v2i = 1 m/s, if in the initial state the masses are moving perpendicularly to each other (the angle between their velocities being 90.