You're using a rope to pull a sled at constant velocity across level snow,with coefficient of kinetic friction 0.050 between sled and the snow. The sled is loaded with physics books, giving a total mass of 21 kg. A) With what force should you pull with the rope horizontal? Express your answer to two significant figures and include the appropriate units. B) Repeat for the rope at 30 above horizontal. Express your answer to two significant figures and include the appropriate units.