Brian is trying to pull Julie on a sled across a flat snowy field. Brian pulls on a rope attached to the sed. His pulling force is directed forward and upwards at a 30 degree angle above horizontal. Julie's mass is 50kg and the sleds mass is 8kg. If the coefficient of static friction among the sled runners and snow is 0.10, how much force should Brian exert on the rope to start moving the sled?