A 45.0 kg girl is standing on a 150 kg plank. The plank,originally at rest, is free to slide on a frozen lake, which is aflat, frictionless surface. The girl begins to walk along theplank at a constant velocity of 1.50 m/s to the right relative tothe plank.
What is her velocity relative to the surface of the ice?
What is the velocity of the plank relative to the surface of the ice?