PhysPup + sled 15.0° 0.40 m PhysPup 1.60 m lands here Like all superheroes, the clairvoyant crime-fighting corgi known as Physpup (alias Dogtor Nose-tra-paw-mus “Momo" Beckwith) typically needs some R&R time after a long day of rescuing babies and biting villains’ ankles. One wintry day, after busting up a counterfeit biscuit manufacturing operation, Physpup (mass mp=3.00 kg) retreats to the nearby safe house, climbs into his trademark yellow inflatable raft (mass mR = 1.00 kg), and spends the afternoon sledding down the rooftop into a soft pile of fresh-fallen snow. Some other details worth noting: The roof of the safe house is inclined at 15.0° above the horizontal. PhysPup starts each sledding run from rest at a vertical distance of 0.40 m above the edge of the roof, and the top of the snow pile is located a vertical distance of 1.60 m below the edge of the roof. The surface of the roof is “ruff," because of course it is. The coefficient of kinetic friction between the roof and PhysPup's raft is µk = 0.0800. Air resistance is negligible because PhysPup doesn’t wear a cape while he’s off duty. PhysPup wears a seat belt in the raft so that he and the raft travel as one object. (a) Calculate the magnitude of the friction force acting on the raft while PhysPup slides down the roof. (b) Calculate the work done by friction as PhysPup slides from the top of the roof to the edge of the roof. (c) Calculate the speed of the PhysPup + raft system at the instant they leave the rooftop.