Question

A dog sled driver hitches a new dog to his sled to test the dog’s pulling power. The harnesses are all set so the dog will exert a purely horizontal force, but the dog refuses to move. Instead, he barks the following message to the driver: “I know physics. The sled will pull back just as hard as I pull it, so the net force will be zero. No force, no acceleration. So, why even try?” Using free body diagrams and Newton’s 2nd and 3rd laws, explain why the dog’s logic is faulty. (He’s pulling the driver’s leg?).

Answer 1