A thermos bottle containing coffee is vigorously shaken. If the coffee is considered as a system, then the temperature of the coffee will

Options

A. increase slightly
B. fall
C. remain the same
D. never be determined

Answer

To solve the question regarding the temperature change of coffee in a thermos bottle when shaken, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the System**:
- The coffee in the thermos bottle is considered as a system. The thermos bottle is designed to be an insulated container, minimizing heat exchange with the environment.

2. **Effect of Shaking**:
- When the thermos bottle is vigorously shaken, the movement causes the coffee to agitate. This agitation increases the kinetic energy of the coffee molecules.

3. **Kinetic Energy and Temperature Relationship**:
- Temperature is a measure of the average kinetic energy of the molecules in a substance. Therefore, if the kinetic energy of the molecules increases, the temperature of the coffee must also increase.

4. **Conclusion**:
- Since the kinetic energy of the molecules increases due to shaking, the temperature of the coffee will increase slightly.

5. **Final Answer**:
- The correct option is that the temperature of the coffee will increase slightly.