A beaver of mass 10.0 kg is sliding at 1.50 m/s along a frictionless, horizontal, ice- covered river when it encounters a rough patch 2.20 m long. The coefficient of kinetic friction between this patch and the beaver's fur is 0.100. After crossing the rough patch and returning to friction-free ice, the beaver slides down an icy, frictionless hill 0.50 m high. a. How fast is it moving when it gets to the bottom of the hill? b. How much internal energy was generated in crossing the rough patch? (Hint: how much work was done by friction?) c. Right after the beaver gets to the bottom of the hill, as unbelievable as it is, it suddenly encounters a spring with a spring constant of 500 N/m. How far does it compress the spring before coming happily to rest