Asked by Mangupa

The girl begins to walk along the plank a constant velocity of 1.815 m/s to the top right relative to the plank, originally at rest, is free to slide on a frozen lake, which is flat, frictionless surface. The 54.45-kg girl standing on a 181.5-kg plank.
a. What is her velocity relative to the surface of the ice?
b. What is the velocity of the plank relative to the surface of the ice?