need help please

1. A dog walks a distance dl north and then d2 NE. How far is the dog from the start? 2 . Ball 1 is dropped from rest from a height h above the ground. Ball 2 is thrown vertically upward from the ground at the instant that the first ball is released. What is the initial speed of ball 2 if the two balls are to meet at a height h/2 above the ground? 3. A box of mass M is pulled upward with a rope. What is the tension in the rope that will give the box an acceleration a? 4. A hockey puck is given an initial speed of 20.0 m/s on a frozen pond. The puck remains on the ice and slides 120m before coming to rest. Determine the coefficient of friction between puck and ice