Question

question 60
a swimming pool is 4.2 m deep. what is the total pressure, from the water and the atmosphere above it, at the bottom of this pool. assume the density of fresh water.
142,000 pa
214,000 pa
201,000 pa
182,000 pa

Explanation:

Step1: Recall Pressure Formulas

Total pressure \( P_{total} \) at the bottom of the pool is the sum of atmospheric pressure \( P_{atm} \) and hydrostatic pressure \( P_{hydro} \).
Atmospheric pressure \( P_{atm} \approx 101325 \, \text{Pa} \) (standard).
Hydrostatic pressure formula: \( P_{hydro} =
ho g h \), where \(
ho = 1000 \, \text{kg/m}^3 \) (density of fresh water), \( g = 9.8 \, \text{m/s}^2 \), \( h = 4.2 \, \text{m} \).

Step2: Calculate Hydrostatic Pressure

Substitute values into \( P_{hydro} \):
\( P_{hydro} = 1000 \times 9.8 \times 4.2 \)
\( P_{hydro} = 1000 \times 41.16 = 41160 \, \text{Pa} \).

Step3: Calculate Total Pressure

\( P_{total} = P_{atm} + P_{hydro} \)
\( P_{total} \approx 101325 + 41160 = 142485 \, \text{Pa} \approx 142000 \, \text{Pa} \) (rounded).

Answer:

142,000 Pa