Physical independence of force is a Consequcnce of

Options

A. 1.first law of motion
B. 2. second law of motion
C. 3. third law of motion
D. 4. all of these laws

Explanation

To solve the question, "Physical independence of force is a consequence of:", we will analyze the three laws of motion proposed by Sir Isaac Newton and determine which one relates to the concept of physical independence of force.

### Step-by-Step Solution:

1. **Understanding the First Law of Motion**:
- The first law of motion states that a body at rest will remain at rest and a body in motion will continue in motion with the same speed and in the same direction unless acted upon by an external force. This law implies that forces are necessary to change the state of motion of an object.
- **Conclusion**: The first law introduces the concept of inertia and the necessity of force to change an object's motion, which indicates the physical independence of forces acting on different objects.

2. **Understanding the Second Law of Motion**:
- The second law of motion states that the acceleration of an object is directly proportional to the net force acting on it and inversely proportional to its mass (F = ma). This law describes how forces affect motion but does not specifically address the independence of forces.
- **Conclusion**: While the second law is crucial for understanding the relationship between force and motion, it does not establish the concept of physical independence of forces.

3. **Understanding the Third Law of Motion**:
- The third law of motion states that for every action, there is an equal and opposite reaction. This law describes the interaction between two bodies but does not imply that forces are independent of each other.
- **Conclusion**: The third law emphasizes the interaction of forces but does not contribute to the idea of physical independence of force.

4. **Final Conclusion**:
- After analyzing all three laws, we find that the concept of physical independence of force is a direct consequence of the first law of motion. The first law emphasizes that an object will not change its state of motion unless acted upon by an external force, which supports the idea that forces can act independently on different objects.

### Answer:
The physical independence of force is a consequence of the **First Law of Motion**.

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