The speeds of the molecules in fluids can get much higher than those of solids. Fluid molecules can move independently past one another so that is why fluids can flow and solids can not.
Flow rate: How quickly a fluid flows in a given amount of time.
Dynamic: Systems involving moving fluids are said to be dynamics.
Aerodynamics: Gas dynamics, moving around solid objects.
Hydrodynamics: Motion of liquids around solid objects.
Viscosity: The resistence that a fluid has to flowing and movement. Different substances are composed of different particles have have different force and attraction. This helps to explain why fluids can have different v viscosities. Ketchup is thick and has a high viscosity like syrup, but it less viscous than ketchup.
Laminar: When the flow of fluid around an object is smooth and uniform.
Buoyancy: The upward force on an object that is less dense than itself.
Weight is a measurement of the force of gravity pulling on the object. It is measured in Newtons. Because gravity is not the same everywhere in the universe, an object's weight varies accordingly.
Volume is a measure of the amount of space occupied by a matter.
The key idea that Archmedes realized is still known as Archemedes' principle. The buoyant force on an object immersed in water is equal to the weight of the fluid that the object displaces.
Density is the mass of a substance per unit volume of that substance.
Formula: Mass/Volume or D=M/V. Eg. Density=1000kg/1m cubed=1000kg/m cubed.
g/cm cubed and kg/m cubed.
The braking system of a vehicle is usually a hydrolic one because it is more powerful and quick. But in big trucks, the brake system is pneumatic because it is 1/3 compressible and thus, more steady for bigger masses.