Esteban pulls a 62 kg sled trough the snow. On the back of the sled is his 50 kg sack of fishing equipment. The coefficient of sliding friction between the sled and the snow is 0.07 and the coefficient between the sled and the sack is 0.1. While pulling, the fishing rod sticking out of his sack catches a tree branch, but Esteban doesn’t notice and keeps walking. What force does Esteban need to exert to keep the sled moving with a constant velocity while the sack is pulled back across it?