When a sound wave travels from water to air , it

Options

A. bends towards normal
B. bends away from normal
C. may bend in any direction
D. date insufficient

Explanation

To solve the problem of how a sound wave behaves when it travels from water to air, we can follow these steps:

### Step 1: Understand the Concept of Refraction
When a wave passes from one medium to another, it can change speed and direction. This phenomenon is described by Snell's Law, which relates the angles of incidence and refraction to the velocities of the wave in the two media.

### Step 2: Identify the Media and Their Properties
In this case, the sound wave is traveling from water to air. We need to know the velocities of sound in both media:
- Velocity of sound in water (V1)
- Velocity of sound in air (V2)

### Step 3: Compare the Velocities
It's known that the velocity of sound is greater in water than in air:
- V1 (in water) > V2 (in air)

### Step 4: Apply Snell's Law
According to Snell's Law:
\[ \frac{\sin i}{\sin r} = \frac{V1}{V2} \]
Where:
- \( i \) = angle of incidence
- \( r \) = angle of refraction

Since V1 > V2, we can conclude that:
\[ \frac{V1}{V2} > 1 \]

### Step 5: Analyze the Implications
From the relationship \( \frac{\sin i}{\sin r} = \frac{V1}{V2} \):
- If \( \frac{V1}{V2} > 1 \), then \( \sin i > \sin r \).
- Since sine is an increasing function in the range of 0° to 90°, this means:
\[ i > r \]

### Step 6: Determine the Direction of Bending
Since the angle of incidence (i) is greater than the angle of refraction (r), the sound wave bends towards the normal when it travels from water to air.

### Conclusion
Thus, when a sound wave travels from water to air, it bends **towards the normal**.

### Final Answer
The sound wave bends towards the normal.

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