Six dogs pull a two-person sled with a total mass of 220 kg. the coefficient of kinetic friction between the sled and the snow is 0.08. the sled accelerates from rest at 0.75 m/s2 until it reaches a speed of 12 km/h. a) what is the work done by the dogs in the accelerating phase? b) what is the maximum power output by the dogs? c) what is the pulling force from the dogs (assumed to be horizontal)?