Forces on wires in code

You will write three functions about the force of a magnetic field on a wire. They use $F = BIL\sin\theta$.

The idea. A straight wire at an angle $\theta$ to a uniform field feels $BIL\sin\theta$. In a uniform field a bent wire feels the force of the straight wire between its ends. A rod hung on two threads in a field that points up swings out until $\tan\varphi = \dfrac{BIL}{mg}$.

Your tasks.

1. In force_on_wire, return the force in N. The angle is in degrees.
2. In chord_length, points is a list of corners (x, y) of a bent wire, in m. Return the distance in m from the first point to the last. That is the effective length.
3. In hanging_angle, return the angle $\varphi$ of the threads with the vertical, in degrees.