A snowmobile climbs a hill at velocity v-up. The slope of the hill is a 1 ft rise for every 40 ft of distance. The resistive force of the snow is equal to 4.1 percent of the weight of the snowmobile. How fast will the snowmobile move downhill, assuming the engine delivers the same power? (Express the answer in mi/hr.) Data: vup = 17.0 mi/hr.