In my last post, I show how I thought I could solve for the magnetic force of a solenoid. I decided to use the equation of a solenoid with no core as the magnetic energy and find the force by plugging in flux density B of a solenoid with its plunger at an arbitrary position, then dividing it by the length. I didn't think about the fact that Force = change in energy / length. Instead I was trying to find force using a specific position, which doesn't really make much sense. I realized this the day after posting it, but I haven't had time to work on this lately, so In the next post I will rework the math.