Help with code.

[Jon]

I realize this isn't the most efficient way to create a pendulum but I'm lost as to why it isn't working, any help?

[Bruce Sherwood]

The following statement doesn't make sense, because even if you assume that the force of the rod points along the rod you have to get its magnitude from a vector calculation:

magFarm=(((box.m)*(v**2))/R)-mag(Fg) #magnitude of force of arm

Let w = z component of angular velocity

Neglect mass of rod

dL/dt = torque, around the pivot point

L = md^2w, where L is z component of angular momentum, d is length of rod

md^2 dw/dt = -mgdsin(theta), where w = dtheta/dt

Then:

w = w - ((g/d)*sin(theta))*dt

theta = theta + w*dt