1) A 45.0-kg girl is standing on a134-kgplank. 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 of1.32m/sto the right relative to the plank. (Let the direction the girl is moving in be positive. Indicate the direction with the sign of your answer.)

(a) What is her velocity relative to the surface of ice? ___________m/s (b) What is the velocity of the plank relative to the surface of ice? __________m/s

2) A 70.0-kg person throws a 0.0500-kg snowball forward with a ground speed of 33.5 m/s. A second person, with a mass of 59.5 kg, catches the snowball. Both people are on skates. The first person is initially moving forward with a speed of 3.00 m/s, and the second person is initially at rest. What are the velocities of the two people after the snowball is exchanged? Disregard the friction between the skates and the ice. (Take the direction the snowball is thrown to be the positive direction. Indicate the direction with the sign of your answer.) thrower __________ m/s (Give your answer to at least three decimal places.) catcher __________ m/s