When an ideal gas is compressed adiabatically , its temperature rises the molecules on the average have more energy than before. The kinetic energy increases,

Options

A. because of collision with moving parts of the wall only.
B. because of collisionws with the entire wall.
C. because the molecules gets accelerated in their motion inside the volume.
D. because the redistribution of energy amongst the molecules.

Explanation

To solve the question regarding the increase in kinetic energy of an ideal gas when compressed adiabatically, we can follow these steps:

### Step-by-Step Solution:

1. **Understand Adiabatic Compression**:
- Adiabatic compression means that the gas is compressed without any heat exchange with its surroundings. This means that all the work done on the gas results in an increase in its internal energy.

2. **Visualize the Setup**:
- Imagine a cylinder with a piston. Initially, the gas occupies a certain volume. When the piston is pushed down, the volume of the gas decreases.

3. **Effect of Compression on Temperature**:
- As the volume decreases, the gas molecules are forced closer together. Since there is no heat exchange, the work done on the gas increases the kinetic energy of the gas molecules, leading to an increase in temperature.

4. **Molecular Collisions**:
- The gas molecules collide with each other and with the walls of the cylinder. When the piston moves, the molecules also start colliding with the moving piston. This increases their average kinetic energy.

5. **Energy Redistribution**:
- The energy that was initially in the form of work done on the gas is redistributed among the gas molecules. As they collide more frequently with the walls and each other, their kinetic energy increases.

6. **Identify the Correct Reason**:
- The increase in kinetic energy of the gas molecules can be attributed to the collisions with the moving parts of the wall (the piston). This is because the molecules gain energy from these collisions, leading to an increase in their average kinetic energy.

7. **Conclusion**:
- Therefore, the correct answer to the question is that the kinetic energy increases because of the collisions with the moving parts of the wall only.

### Final Answer:
The correct option is: **because of the collisions with moving parts of the wall only.**

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