Magnetic Force calculation

Formula:

F = (n x i)² x magnetic constant x a / (2 x g²) Where, F = Force, i = Current, g = Length of the gap between the solenoid and a piece of metal, a = Area n = Number of turns, Magnetic constant = 4 x PI x 10^-7.

Force calculation:

F=(N∗I)2μ0A(2g2)$F=(N\ast I{)}^2{\mu }_0{\displaystyle \frac{A}{(2g^2)}}$

Where:

μ0=4π∗10−7${\mu }_0=4\pi \ast {10}^{-7}$
F$F$ is the force in Newtons
N$N$ is the number of turns
I$I$ is the current in Amps
A$A$ is the area in length units squared
g$g$ is the length of the gap between the solenoid and a piece of metal