A 46 kg girl is standing on a 145 kg plank. The plank, originally at rest, is free to slide on a frozen lake, which is a flat, frictionless surface.

A 46 kg girl is standing on a 145 kg plank. The plank, originally at rest, is free to slide on a frozen lake, which is a flat, frictionless surface. The girl begins to walk along the plank at a constant velocity of 1.52 m/s relative to the plank. What is her velocity relative to the ice surface?