A man is pulling a 13-kg sled across a flat, snowy surface. He holds the handle of the sled at a 30° angle with the ground.
What is the minimum pulling force (F) to the nearest newton that the man must exert to keep the sled moving? (Use the following constants: coefficient of sliding friction = 0.15; acceleration due to gravity = 9.8 m/s2, cos 30 = 0.87.)
A. 9.5 NB. 20 NC. 19 ND. 22 NE. 130 N