A 300-kg bear grasping a vertical tree slides down at constant velocity. the friction force between the tree and the bear is

The friction force between the tree and the bear is 3000 N. The acceleration is 0 since the bear slides down at a constant velocity. The sum of the forces is 0. Thus;

Upward friction + downward weight = 0

F-mg = 0

F = mg

F = (300 kg) (10 m/s² the acceleration due to gravity)

F = 3000 N frictional force