Inclined Plane Friction

1. Define the term "coefficient of friction" and explain what it represents in the context of an object on an inclined plane.

2. Explain why the normal force is equal to mg⋅cos(θ) for an object on an inclined plane. Use a free body diagram to support your answer.

3. A block of wood with a mass of 10 kg is resting on an inclined plane that makes an angle of 25° with the horizontal. If the coefficient of static friction between the block and the plane is 0.4, calculate the force of friction acting on the block.