+ 3 Gravity: O on off Gravity Force Velocity Path Grid Star Mass 0.5 Our Sun 1.5 2.0 Planet Mass 0.5 Earth 1.5 2.0 O Fast 191 Earth Days Normal Clear SlowKepler 3rd Law relates the period of revolution T of a planet orbiting the Sun (of mass M) with its semi-major axis a = 4.752 03 GM T2 Restart, and increase the Star Mass to 1.5. Use this setting to check your answers to the questions 15. Now by looking at the simulation: 20. What is the approximate value of the period now? 21. What is the approximate ratio of the aphelion over the perihelion? 22. Use Kepler 3rd Law to calculate the semi-major axis a