The equation for pressure is

Options

A. hg/d
B. hdg
C. hd/g
D. h/dg

Explanation

To find the equation for pressure in a fluid, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Concept of Pressure**:
Pressure is defined as the force exerted per unit area. In the context of fluids, pressure increases with depth due to the weight of the fluid above.

2. **Identify the Variables**:
- Let \( \rho \) (or \( D \) as given in the options) be the density of the liquid.
- Let \( g \) be the acceleration due to gravity.
- Let \( h \) be the height of the liquid column above the point where pressure is being measured.

3. **Use the Formula for Pressure in a Fluid**:
The formula for pressure at a depth \( h \) in a fluid is given by:
\[ P = \rho g h \]
Here, \( P \) is the pressure, \( \rho \) is the density of the liquid, \( g \) is the acceleration due to gravity, and \( h \) is the height of the liquid column.

4. **Modify the Formula According to Given Options**:
In the problem, the density is represented as \( D \) instead of \( \rho \). Therefore, we can rewrite the pressure formula as:
\[ P = D g h \]

5. **Identify the Correct Option**:
From the options provided, we need to find which one matches our derived formula \( P = D g h \).
- The correct option is the one that states \( P = D g h \).

### Conclusion:
The equation for pressure in a fluid at a depth \( h \) is:
\[ P = D g h \]
where \( D \) is the density of the liquid, \( g \) is the acceleration due to gravity, and \( h \) is the height of the liquid column.

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