Suppose you are 80 cm from a plane mirror. what area of the mirror is used to reflect the rays entering one eye from a point on the tip of your nose if your pupil diameter is 6.7 mm ?

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.