1. If vector U= 3i + 4j, vector V= 5 k and vector W= 4i - 3j, find the angle between U and V-W .
2. At the same time that ball X rolls off a platform on an airless extra-solar planet 8.00 meters high at a speed of 6.00 m/s, ball Y is dropped from the edge of the platform. Ball Y hits the ground after 1.00 second. Find g on this extra-solar planet.
3. The mass of ball X is 12.0 kilograms and the mass of ball Y is 9.0 kilograms. Find the momentum of ball X and the momentum of ball Y in problem 2 at the time when ball X hits the ground.
4. Find the gravitational forces of a) the planet on ball X, b) ball X on ball Y, c) ball Y on ball X and d) ball Y on the planet at the time when ball Y hits the ground.