Which force always opposes motion ?

Options

A. Magnetic force
B. Electrostatic force
C. Friction
D. Muscular force

Explanation

**Step-by-Step Solution:**

1. **Understanding Forces**: Begin by recognizing that there are various types of forces that can act on an object. These include magnetic force, electrostatic force, muscular force, and frictional force.

2. **Identifying Motion**: When an object is in motion, it can be influenced by different forces. Some forces can help in moving the object, while others can resist or oppose that motion.

3. **Analyzing Friction**: Friction is a force that acts between two surfaces in contact. It always acts in the opposite direction to the motion of the object. For example, if an object is sliding to the right, the frictional force will act to the left.

4. **Conclusion**: Based on the analysis, the force that always opposes motion is the **frictional force**. It resists the relative motion between surfaces in contact.

**Final Answer**: The force that always opposes motion is the **frictional force**.

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