Most wire or string is made with a circular cross section of some particular radius and diameter. The area of that cross section is the well known A = pi*R² which is colloquially pronounced as “pie ...

The volume of any cylinder is the area of the cross-section multiplied by its height. This is given by the formula \(V\) = π\(r\)²\(h\) , where \(r\) is the radius of the circular cross-section ...

Researchers have now derived an equation describing this phenomenon, demonstrating that beyond liquid viscosity and compressibility, variations in tube cross-sectional area contribute to wave ...