Electromagnet simulator. Change the sliders to see how many iron filings you can pick up. Needs calculations. Needs iron filings to appear on the electromagnet and disappear from the ground. Use random to make it a bit more realistic. Extension: Introduce more variables (see below)
Force = C A n I / d C = constant A = area of end of solenoid n = number of turns of coil I = current d = length of solenoid
