Dive to the bottom of a pool and your ears feel the weight of all the water above you. Go deeper and the squeeze grows; switch to a denser liquid and it grows faster. The shape of the container makes no difference at all, only how far down you are.
The change in pressure with depth in a liquid is Δp = ρgΔh, where ρ is the density of the liquid, g is the gravitational field strength and Δh is the depth below the surface. Pressure acts equally in all directions.
The change in pressure beneath a liquid surface equals the density times the gravitational field strength times the change in depth.
It depends on depth and density only, not on the shape of the container.
Change the depth and the density of the liquid. The pressure reading climbs steadily with depth, and a denser liquid pushes harder at the same depth.
Four quick checks on the equation, depth, and direction. Each correct answer earns XP and lights this skill on your star map.
The change in pressure with depth in a liquid is calculated using...
As you go deeper into a liquid, the pressure...
At a given depth, the liquid pressure depends on the depth, the gravitational field strength, and...
At a point in a liquid, the pressure acts...
The defining equation and its rearrangement for depth:
Find the pressure due to a column of water 3.0 m deep. Density of water = 1000 kg/m³, g = 9.8 N/kg.
Liquid pressure depends on depth and density, never on the shape or the amount of liquid. A narrow tube and a wide tank filled to the same depth give exactly the same pressure at the bottom. Use the vertical depth below the surface for Δh, and the density of the liquid for ρ, not the density of anything floating in it.
Unlocks once the four checks above are done. Worth more XP, written in the style of Paper 2.
Find the pressure due to a 2.0 m depth of water. Density of water = 1000 kg/m³, g = 10 N/kg.
Two containers of different shapes hold water to the same depth. The pressure at the bottom is...
At what depth in seawater is the pressure 51500 Pa? Density of seawater = 1030 kg/m³, g = 10 N/kg.
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