Which of the following is a mechanical wave?

Options

A. Radio waves
B. X-rays
C. Light waves
D. Sound waves

Answer

To determine which of the following is a mechanical wave, we can follow these steps:

### Step 1: Understand the Definition of Mechanical Waves
Mechanical waves are defined as waves that require a medium (solid, liquid, or gas) to propagate. They cannot travel through a vacuum.

### Step 2: Understand the Definition of Electromagnetic Waves
Electromagnetic waves do not require a medium to travel. They can propagate through a vacuum and include waves such as radio waves, microwaves, infrared, visible light, ultraviolet, X-rays, and gamma rays.

### Step 3: Analyze the Given Options
We need to evaluate each of the options provided to identify which one is a mechanical wave.

1. **Radio Waves**: These are electromagnetic waves and do not require a medium.
2. **X-rays**: These are also electromagnetic waves and do not require a medium.
3. **Light Waves**: Light is an electromagnetic wave and can travel through a vacuum.
4. **Sound Waves**: Sound waves are mechanical waves as they require a medium (air, water, or solid) to travel.

### Step 4: Identify the Correct Answer
From the analysis of the options:
- Options 1, 2, and 3 (radio waves, X-rays, and light waves) are all electromagnetic waves.
- Option 4 (sound waves) is the only mechanical wave.

Thus, the correct answer is **sound waves**.

### Final Answer
**Sound waves** are the mechanical wave among the options provided.

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