A water tank is filled to a depth of 10 m and the tank is 20 m above ground.The water pressure at ground level in a hose 2 cm in diameter is closest to: A)3.9 × 105 N/m² B)2.0 × 104 N/m² C)9.2 N/m² D)The cross-sectional area of the tank is needed.

Question

Quizplus · Accepted Answer

The water pressure at ground level is determined by the height of the water column above it. The pressure due to a column of fluid of height h and density ρ is given by the formula P = ρgh, where g is the acceleration due to gravity.

Here, the height of the water column is (20 + 10) = 30 m. The density of water is 1000 kg/m^3 and the acceleration due to gravity is 9.8 m/s^2.

The pressure at ground level is therefore: 
P = (1000 kg/m^3) x (9.8 m/s^2) x (30 m) = 2.94 × 10^5 N/m^2

We can convert this to N/m^2=Pa using the definition 1 Pa = 1 N/m^2.

Therefore, the pressure is closest to 2.94 × 10^5 Pa, which is approximately 3.9 × 10^5 N/m^2.

The cross-sectional area of the hose is not needed to determine the pressure.

A Water Tank Is Filled to a Depth of 10