nm⁴
nanometer to the fourth
Area moment of inertiaexact by definition
The nanometre to the fourth is 10⁻³⁶ m⁴, exact by prefix. It appears in nanomechanics, where the bending stiffness of a nanotube, nanowire or DNA molecule is modelled as a beam and the second moment of area comes out in nm⁴.
Watch out: Beam theory at this scale is a model of convenience rather than a description of the material. Surface effects, discrete atomic structure and thermal fluctuation all matter, and a bending stiffness in nm⁴ times a modulus is an effective value fitted to experiment, not a geometric fact.
| 1 nm⁴ | 1.0000000e-24 mm⁴ |
Solvers that use area moment of inertia