Which of the following are predicted by Kepler's laws for the motion of planets orbiting the Sun? I.Planets move in elliptical orbits about the Sun. II.Planets move such that in equal periods of time a line from the Sun to the planet sweeps out equal areas. Ill. The speed of a planet is greatest when it is farthest from the Sun. Select one: a. I and Ill b. I, II, and Ill c. II and Ill d. I and Il What is the direction of the net force on an object that is travelling in a circle at a constant speed on a horizontal frictionless surface Select one: a. radially outward O b. radially inward c. tangential to the circle in the direction of travel d. the net force is zero If the orbit of the moon about Earth was a circle, which of the following would be true? I. The moon is accelerating toward Earth. Il. The velocity of the moon is constant. Select one: . a. I only b. II only O c. Neither is true. What is the radius of the circular motion if an object travelling at 2.64 m/'s experiences a centripetal acceleration of 3.24 m/s?? Select one: . a. 0.815 m O b. 3.98 m O c. 2.15 m O d. 1.23 m Mass A, moving in a circle of radius 1.50 m, takes 2.00 s to make one revolution. Mass B requires 1.00 s to make one revolution of a circle with a radius of 3.00 m. If both masses have constant speeds, what is the ratio of the centripetal force (F) acting on A compared to that acting on B? Select one: FB Ob. FA - F O C. FA F. O d