The symbol V dentones the element Vanadium. Or if your working in Roman numerals then V represents the number 5.
Velocity's' symbol is represented by a simple: "V".
V
The symbol for a vector is typically represented by an arrow placed above the variable name or by using boldface type. For example, a vector quantity velocity "v" would be represented as a vector v or $\vec{v}$.
Vanadium
5000 is represented in Roman numerals by a 5 symbol, which is V with either a horizontal bar above it (which I can't show using my keyboard) or by a V enclosed in brackets = (V). 50 is represented by the symbol L, so 5050 can be written as (V)L
Vf
5000 is represented in Roman numerals by a 5 symbol, which is V with either a horizontal bar above it (which I can't show using my keyboard) or by a V enclosed in brackets = (V). 500 is represented by D so 5500 can be expressed by the symbols (V)D
An unknown number represented by a letter or symbol is a variable.
Aries' symbol is the ram.
Be is the chemical symbol for Beryllium.
In general density is represented by the Greek symbol rho (ρ)
The symbol for average velocity is "v-bar" or v with an overscore.