In this guided inquiry PhET online lab your students will investigate the pressure in fluids. This includes liquids and air. By the end of this online lab students should be able to (1) describe how the pressure in air and water changes as a function of depth, (2) explain how the shape of the liquid container affects pressure, (3) describe all variables that affect pressure and (4) determine the density of an unknown fluid. This online lab is intended to be used with the Under Pressure (HTML5)