Heat-Flow Dynamics

When more energy is added to a system than is lost, its temperature increases. Conversely, when more energy is lost than is added, its temperature decreases.

Pressure

The flow of water out of a tank is caused by differences in water pressure.

The pressure at any point under the water increases with the height of the water above it. The pressure at any point under the water decreases with the depth of the water below it. The pressure at any point under the water is the same in all directions. Pressure doesn’t point in any particular direction. It is a force that acts equally in all directions.

Flow in Pipes

If a barrier in a pipe has a net force on it, then if the barrier was removed, the flow through that pipe would be in the direction of the net force. To speed up, water must flow from a region of higher pressure to lower pressure. To slow down, water must flow from a region of lower pressure to higher pressure.

Buoyancy

The buoyant force on an object is equal to the weight of the water that it displaces.