Fluids and Gases in motion

Forces > Forces and motion > Fluids and Gases in motion 

Fluids and gases (which together are called fluids) tend to flow easily, which causes a net motion of molecules from one point in space to another. That is why, contrary to the motion of solid objects, fluids change their shape and properties (such as pressure) as they move. The movements of fluids and gases are studied under fluid dynamics. Their study helps us understand many aspects of our world, such as the evolution of stars, ocean currents, weather patterns, plate tectonics and blood circulation.

Connection to Big Idea about energy: Energy transfer in liquids and gases can be transferred by conduction, convection and thermal radiation or by phase changes (evaporation and condensation).

Connection to Big Idea about the universe: Stars are made up of an ionised fluid called plasma. Stellar energy is produced in the centre of stars through nuclear fusion and it is transported outwards via radiation and convection.

Connection to Big Idea about particles: Energy can be transferred by conduction, convection and radiation. All these processes involve particles that form the bodies that participate at the phenomenon. Energy transfer can occur either through particles collisions (conduction), through particle’s collective motion (convention) or finally through the emission of electromagnetic radiation (thermal radiation).  

Connection to Big Idea about Earth: Earth is full of liquids and gases in motion. The oceans and the Earth’s hot liquid layers in its interior, the outer core and the mantle are examples of such liquids. The air we breathe and gases emitted by volcanoes are examples of the gases in motion on Earth. Changing weather conditions occur due to the motion of gases and liquid in the Earth’s surface and atmosphere.

Subjects related: Chemistry, Physics

Age ranges: 12-13,13-14,14-15,15-16,16-17,17-18