If action and reaction were to act on the same body

Options

A. the resultant would be zero
B. the body would not move at all
C. both a and b are correct
D. neither a nor b is correct

Answer

To solve the question "If action and reaction were to act on the same body," we need to analyze the implications of Newton's Third Law of Motion, which states that for every action, there is an equal and opposite reaction.

### Step-by-Step Solution:

1. **Understanding Action and Reaction**:
- According to Newton's Third Law, when one body exerts a force (action) on another body, the second body exerts a force (reaction) of equal magnitude but in the opposite direction on the first body.

2. **Considering Forces on the Same Body**:
- If both the action and reaction forces act on the same body, they will be equal in magnitude and opposite in direction.

3. **Calculating the Resultant Force**:
- Since the action and reaction forces are equal and opposite, when we sum these forces, the resultant force on the body will be zero.
- Mathematically, if we denote the action force as \( F \) and the reaction force as \( -F \), the resultant \( R \) can be expressed as:
\[ R = F + (-F) = 0 \]

4. **Determining the Motion of the Body**:
- With a resultant force of zero, according to Newton's First Law of Motion, the body will not accelerate. If it is at rest, it will remain at rest; if it is in motion, it will continue to move with constant velocity.

5. **Conclusion**:
- Therefore, both statements in the options are correct:
- The resultant force is zero.
- The body would not move at all (if it was initially at rest).

### Final Answer:
- The correct option is **Option 3**: Both A and B are correct.

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