Understanding the Concept

* Constant Velocity: When an object moves at a constant velocity, the net force acting on it is zero. This means all forces are balanced.

* Friction: Friction is a force that opposes motion between two surfaces in contact.

Solution

1. Forces Acting on the Block:

* Applied Force (F_applied): 6 N (the force dragging the block)

* Friction Force (F_friction): This is the force opposing the motion.

2. Balanced Forces: Since the block moves at constant velocity, the applied force and friction force must be equal in magnitude and opposite in direction.

3. Therefore, the friction force between the block and the surface is 6 N.