Help needed! 1: Why were Tycho and Kepler a good team?
2: How did changing the shape of the planet orbits help Kepler explain planetary movement?
3: What is an ellipse?
4: Does Kepler’s 2nd Law of Planetary Motion apply to satellites? Why or why not?
5: What made it possible for Kepler to come up with his ideas on planetary motion?

A1-lb collar is attached to a spring and slides without friction along a circular rod in a vertical plane. the spring has an undeformed length of 5 in. and a constant k =25 lb/ft. knowing that the collar is released from being held at a determine, the speed of the collar and the normal force between the collar and the rod as the collar passes through b.