11)

two identical pots, one black and one silver, containing exactly the same amounts of water, are heated to the same

temperature. they are left uncovered and placed in the same room. after 15 minutes the water in the black pot is significantly

cooler than the water in the silver pot. which of these statements best explains this difference?

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.