Question

Difficulty: MediumHydrostatic Pressure

An open industrial mixing vat contains a liquid chemical with a specific gravity of 1.251.25. The liquid in the vat reaches a depth of 4 meters4\text{ meters}. Assuming the density of fresh water is 1,000 kg/m31,000\text{ kg/m}^3 and the acceleration due to gravity is 10 m/s210\text{ m/s}^2, what is the hydrostatic pressure exerted by the liquid at the bottom of the vat? (Enter your answer in kilopascals)

Answer: 50 kPa

Answer

50
The hydrostatic pressure at the bottom of a fluid column is determined by the formula P=ρghP = \rho g h. First, the specific gravity of 1.251.25 indicates the fluid is 1.251.25 times as dense as water, giving a density of 1,250 kg/m31,250\text{ kg/m}^3. Multiplying this density by the acceleration due to gravity (10 m/s210\text{ m/s}^2) and the depth (4 meters4\text{ meters}) yields 50,000 Pascals50,000\text{ Pascals}. Since 1,000 Pa1,000\text{ Pa} equals 1 kPa1\text{ kPa}, this is equivalent to 50 kPa50\text{ kPa}.

Step-by-Step Solution

1
Determine the density of the fluid.
Density = 1,250 kg/m³
Specific gravity is the ratio of the fluid's density to the density of water. Multiplying 1.25 by 1,000 kg/m³ gives the actual density.
2
Calculate the hydrostatic pressure in Pascals.
Pressure = 50,000 Pa
Hydrostatic pressure is the product of density, gravity, and depth (1,250 × 10 × 4 = 50,000).
3
Convert the pressure to kilopascals (kPa).
50 kPa
The question asks for the answer in kilopascals, so divide the Pascal value by 1,000.

Key Concept

Hydrostatic Pressure
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