Dimensional Formula (1 of 2)
- In SI, a quantity can often be expressed in terms of other quantities by means of an equation.
- When a quantity, Q, can be expressed as the product of powers of the base quantities multiplied by a numerical factor k we say that the dimension of the quantity Q, denoted dim(Q), is given by:
where I, J, L, M, N, T and T are the dimension symbols (defined in Table 4.4) for the base quantities and i, j, l, m, n, o and t are called the dimensional exponents.
- The formal expression on the right side of the above equation (ignoring the numerical factor k) is called the dimensional formula for Q.
- Note that the base units shall be listed in the order given in the above formula and that units with a zero exponent may be omitted.
- Examples:
- Dimensional formula = L1 is satisfied by { foot, metre, angstrom, ua }
- Dimensional formula = L1T-1 is satisfied by { metre/second, mile/hour }