A tank with a square base of area `1.0m^(2)` is divided by a vertical parition in the middle. The bottom of the partition has a small hinged door of area `20cm^(2)`. The tank is filled with water and an acid (of relative density 1.7) in the other, both to a height of `4.0m`. Compute to force necessary the force nec cessary to keep the door closed.

Explanation

To solve the problem step by step, we will calculate the force necessary to keep the hinged door closed at the bottom of the tank.

### Step 1: Identify the given data
- Area of the tank base, \( A = 1.0 \, \text{m}^2 \)
- Area of the hinged door, \( a = 20 \, \text{cm}^2 = 20 \times 10^{-4} \, \text{m}^2 \)
- Height of both liquids, \( h = 4.0 \, \text{m} \)
- Density of water, \( \rho_1 = 10^3 \, \text{kg/m}^3 \)
- Relative density of acid = 1.7, so density of acid, \( \rho_2 = 1.7 \times 10^3 \, \text{kg/m}^3 \)
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