Moment of inertia of a body comes into play

Options

A. in a linear motion
B. in motion along a curvec path
C. in rotational motion
D. none of the above

Answer

To solve the question regarding when the role of moment of inertia comes into play, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Moment of Inertia**:
- Moment of inertia (I) is a physical quantity that determines how difficult it is to change the rotational motion of an object. It depends on the mass of the object and how that mass is distributed relative to the axis of rotation.

2. **Identifying the Context**:
- The moment of inertia is relevant in scenarios involving rotational motion. This includes any situation where an object is spinning or rotating around an axis.

3. **Recognizing Key Terms**:
- The terms "rotation" and "rotational motion" are crucial in understanding when the moment of inertia is applicable. If an object is not rotating, the concept of moment of inertia does not apply.

4. **Analyzing the Options**:
- The question likely presents multiple-choice options. We need to identify which option includes terms related to rotation or rotational motion.

5. **Selecting the Correct Option**:
- Based on the analysis, we find that the option that mentions both "rotation" and "motion" is the most relevant. This indicates that the moment of inertia comes into play when an object is in a state of rotation.

6. **Conclusion**:
- Therefore, the correct answer is the option that includes both rotation and motion, as this is when the moment of inertia is significant.

### Final Answer:
The moment of inertia of a body comes into play when the body is in rotational motion. The correct option is the one that mentions both rotation and motion.

---