Whenever the surfaces in contact tend to move or move with respect to each other, the force of friction comes into play

Options

A. only if the objects are solid.
B. only if one of the two objects is liquid.
C. only if one of the two objects is gaseous.
D. irrespective of whether the objects are solid, liquid or gaseous.

Explanation

To solve the question regarding the force of friction and its applicability to different states of matter, we can break it down step by step.

### Step-by-Step Solution:

1. **Understanding Friction**:
- Friction is a force that opposes the relative motion between two surfaces in contact. It comes into play whenever these surfaces tend to move or are already moving with respect to each other.

2. **Types of Matter**:
- Matter exists in three primary states: solid, liquid, and gas. Each state has different properties, but friction can occur in all of them.

3. **Friction in Solids**:
- In solids, friction is commonly experienced when two solid surfaces slide against each other, such as a book sliding on a table.

4. **Friction in Liquids**:
- In liquids, friction is referred to as viscous friction. It occurs when layers of liquid move relative to each other, like water flowing in a river.

5. **Friction in Gases**:
- In gases, friction is known as air resistance or drag. It occurs when gas molecules collide with an object moving through the air, such as a car driving down the road.

6. **Conclusion**:
- The force of friction is not limited to solids; it also applies to liquids and gases. Therefore, the correct answer to the question is that friction can occur irrespective of whether the objects are solid, liquid, or gaseous.

### Final Answer:
The force of friction comes into play irrespective of whether the objects are solid, liquid, or gaseous.

---