The bottom wall of a dam is made thick as:

Options

A. the water exerts less pressure on the bottom wall
B. the water exerts more pressure on the bottom wall
C. it looks good
D. it is a custom

Explanation

To answer the question regarding why the bottom wall of a dam is made thick, we can follow these steps:

### Step 1: Understand the concept of pressure in fluids
Pressure in a fluid is defined as the force exerted per unit area. It is given by the formula:
\[ P = \frac{F}{A} \]
where \( P \) is pressure, \( F \) is the force, and \( A \) is the area.

### Step 2: Recognize how pressure changes with depth
In a fluid, the pressure increases with depth due to the weight of the fluid above. The formula for pressure at a certain depth \( h \) in a fluid is:
\[ P = \rho g h \]
where \( \rho \) is the density of the fluid, \( g \) is the acceleration due to gravity, and \( h \) is the depth.

### Step 3: Apply the concept to a dam
In the case of a dam, as the depth of the water increases, the pressure exerted by the water on the bottom wall of the dam also increases. This means that the deeper the water, the greater the pressure on the dam's bottom wall.

### Step 4: Conclude why the bottom wall is made thick
To withstand the increasing pressure exerted by the water at greater depths, the bottom wall of the dam is constructed to be thick. A thicker wall can better resist the forces acting on it and prevent structural failure.

### Final Answer
The bottom wall of a dam is made thick because the water exerts more pressure on the bottom wall as the depth increases.

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