Physical coefficient is an important number that characterizes some physical property of a technical or scientific object under specified conditions. A coefficient also has a scientific reference which is the reliance on force.
Stoichiometric coefficient of a chemical compound
To find the coefficient of a chemical compound, you must balance the elements involved in it. For example, water: H<sub>2</sub>O. It just so happens that hydrogen (H) and oxygen (O) are both diatomic molecules, thus we have H<sub>2</sub> and O<sub>2</sub>. To form water, one of the O atoms breaks off from the O<sub>2</sub> molecule and react with the H<sub>2</sub> compound to form H<sub>2</sub>O. But, there is one oxygen atom left. It reacts with another H<sub>2</sub> molecule. Since it took two of each atom to balance the compound, we put the coefficient 2 in front of H<sub>2</sub>O: 2 H<sub>2</sub>O. The total reaction is thus 2 H<sub>2</sub> + O<sub>2</sub> â 2 H<sub>2</sub>O.
Examples of physical coefficients
- Coefficient of thermal expansion (thermodynamics) (dimensionless) - Relates the change in temperature to the change in a material's dimensions.
- Partition coefficient (K<sub>D</sub>) (chemistry) - The ratio of concentrations of a compound in two phases of a mixture of two immiscible solvents at equilibrium.
- Hall coefficient (electrical physics) - Relates a magnetic field applied to an element to the voltage created, the amount of current and the element thickness. It is a characteristic of the material from which the conductor is made.
- Lift coefficient (C<sub>L</sub> or C<sub>Z</sub>) (aerodynamics) (dimensionless) - Relates the lift generated by an airfoil with the dynamic pressure of the fluid flow around the airfoil, and the planform area of the airfoil.
- Ballistic coefficient (BC) (aerodynamics) (units of kg/m<sup>2</sup>) - A measure of a body's ability to overcome air resistance in flight. BC is a function of mass, diameter, and drag coefficient.
- Transmission coefficient (quantum mechanics) (dimensionless) - Represents the probability flux of a transmitted wave relative to that of an incident wave. It is often used to describe the probability of a particle tunnelling through a barrier.
- Damping factor a.k.a. viscous damping coefficient (Physical Engineering) (units of newton-seconds per meter) - relates a damping force with the velocity of the object whose motion is being dampened.
References