Aperson on a sled coasts down a hill and then goes over a slight rise with speed 2.7 m/s. the top of the rise can be modeled as a circle with a radius 4.1 m. the sled and occupant have a combined mass of 110 kg. if the coefficient of friction between the snow and the sled is 0.10, what friction force is exerted on the sled by the snow as the sled goes over the top of the rise?
it would be super if you could explain how/why you came to your answer as well.

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.