Lecture-Example (posted before lecture) 9/28 (Wednesday) Example: Which has the greatest centripetal acceleration? Example: Homework: Question 5-8 When someone swings a bucket of water in a vertical circle, the water will not fall off on the top of the circle if the speed is fast enough. Question: how fast? Question: at the bottom, what is the normal force? Homework: Question 5-13: Does an apple exert a gravitational force on the Earth? If so, how large a force? Question: What is the acceleration due to gravitational force near Ea rth's surface: Question: What is the acceleration due to gravitational force near Moon's surface: Homework: Question 6-23 The Earth moves faster in its orbit around the Sun in January than in July. Why