The relationship between electrical conductivity and magnetically damped motion

Varying electrical conductivities of different, non-magnetic metals appears to affect the magnitude of magnetically damped motion. To determine the relationship between magnetic damping and conductivity an experiment was designed using different length tubes of aluminium, copper and brass. The tubes had the same diameter and similar wall thickness. A short, cylindrical neodymium magnet was dropped through the tubes of and the time for the magnet to traverse the tube was recorded using a smartphone camera. These times allowed for the terminal velocity to be calculated for each metal length and the average terminal velocity for each metal was determined. This data was then processed to compare the terminal velocity with known conductivity values. The relationship between the terminal velocities of aluminium, brass and copper and their respective conductivities was found to be inversely proportional; as conductivity increases, terminal velocity decreases. Through this relationship, copper was identified as most effective in magnetically damping motion, exhibiting the largest terminal velocity of all metals and the highest conductivity.