10. A diver is collecting shells under water. They see a very large and beautiful shell so they reach out to pick it up. After several missed attempts to grab the shell, the diver places it in a dive bag and surfaces. At the surface the diver is surprised that the shell is smaller than they thought. Explain this phenomenon.

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.