A planet orbits a star along an elliptical path, as shown in the figure above. How do the planet’s kinetic energy and the total mechanical energy of the star-planet system change as the planet moves from point x to point y?.

You want to test the hypothesis that smoking cigarettes increases the risk of lung cancer. in your experiment, you take 100 people of various ages and genders for each of your groups. one group smokes. the other group does not smoke. the group that does not smoke is called the group