MCAT PHYSICS AND MATH REVIEW lid string metal sheet tank of water front view side corner view The weight of the water above the metal sheet produces a force that pushes down on the sheet. If we divide this force by the area of the sheet, w/A, we get the pressure, due to the water, on the sheet. The formula for calculating this pressure depends on the density of the fluid in the tank ( Pquid ), the depth of the sheet (D), and the acceleration due to gravity (g). P =- W fluid _ MAluid 8 _ PAluid fluid 8 - Pruid ADS = Pquid Dg A A A A Hydrostatic Gauge Pressure Pgauge = Pluid & D of the abou ections This formula gives the pressure due only to the fluid (in this case, the water) in the tank. This is called tostatic gauge pressure. It's called hydrostatic, because the fluid is at rest, and gauge pressure mean ause the which what we don't take the pressure due to the atmosphere into account. If there were no lid on the water tank in the water would be exposed to the atmosphere, and the total pressure at any point in the water woul norma he equal to the atmospheric pressure pushing down on the surface plus the pressure due to the water (th "le gauge pressure). So, below the surface, we'd have