An equinox occurs twice throughout the course of a year, when Earth’s axis points neither toward nor away from the Sun. How does an equinox affect the lengths of day and night? A. Day and night are equal in length.
B. Day is longer than night.
C. Night is longer than day.
D. The sun will not set, resulting in a 24-hour day.
E. The sun will not rise, resulting in a 24-hour night.

Consider a small frictionless puck perched at the top of a fixed sphere of radius r. if the puck is given a tiny nudge so that it begins to slide down, through what vertical height will it descend before it leaves the surface of the sphere? [hint: use conservation of energy to find the puck's speed as a func e conservation of energy to find the puck's speed as a function of its height at what value of this normal force does the puck leave the sphere? ] here on the puck.