After coming down a slope, a 60-kg skier is coasting northward on a level, snowy surface at a constant \(15 \mathrm{~m} / \mathrm{s}\). Her \(5.0-\mathrm{kg}\) cat, initially running southward at \(3.8 \mathrm{~m} / \mathrm{s}\), leaps into her arms, and she catches it.

(a) Determine the amount of kinetic energy converted to internal energy in the Earth reference frame.

(b) What is the velocity, measured in the Earth reference frame, of an inertial reference frame in which the cat's kinetic energy does not change?