Hydrodynamic pressure


  • To describe the pattern of water flow.
  • The effect of water flow on pressures.
  • Predicting pressures in different situations.

Virtual Experiment 

In this virtual simulation, pressure modeling allows students to investigate pressures under and above water, as well as changes in fluid density, gravity, and container shapes and volume. You will work with parts two and three of the simulation.

The figure below shows the functions each button performs.


Part 1. Relationship between water quantity and pressure

Step 1. After turning on the simulation, open the second section. When you turn it on:

  • Atmospheric pressure is expressed in metric units.
  • Fluid type: water.
  • Water density: 1000 kg/m3.
  • Earth’s gravity: 9.8m /s2.
  • Display a grid showing the depth of the container.

Step 2. Measure the pressure of both parts of the container with a barometer. You will see that their pressures are equal to each other at the same depth.

Step 3. Turn off the atmospheric pressure and measure the pressure again.

Step 4. Switch from metric to atmospheric units of measurement. Measure the pressure for the states with atmospheric pressure off and on.

Step 5. Drain some of the water through the faucet located at the bottom of the container. The volume of water has decreased by the same amount in both containers. Measure the pressure. Select the unit of measurement yourself. 

Step 6. Fill the container with water. Measure the pressure in each part of the containers. 

Step 7.You can measure the pressures and do different experiments by changing the gravitational attraction, types of liquids as you wish. 

Part 2. Changing the pressure due to gravity

Step 8.Measure the pressure in each part of the water containers using a barometer.

Step 9. Place 250 kilograms of kettlebell in the container. Observe the change in pressure without moving the barometer from a standing position. Keep an eye on the water level. 

Step 10. Place another 250 kg and 500 kg of kettlebells. Observe the change in pressure. 

Step 11. Take the kettlebell stone that is on top of the container. Watch the changes in the container. 

Step 12. You can try measuring and experimenting with the pressure by changing the gravitational pull, types of liquids, additional parameters if needed.

Step 13. Draw conclusions by looking at the experiments you have done. How does changing units of measurement affect pressure readings? How does adding weight affect the pressure in different parts of the container?


In this virtual lab, you have explored the relationship between pressure, the amount of water, and gravity. You:

  • Measured the pressure in different parts of a container of water.
  • Observed the change in pressure as the amount of water changed.
  • Investigated the effect of gravity on pressure.
  • Conducted experiments with different types of liquids and gravitational attraction.