Series & Parallel Combination

If one end of a long flat spiral spring is fixed and the lower end is pulled by a short jerk and released, longitudinal waves are produced. The apparatus consists of a spiral spring about 25mm diameter and 10cm length. The upper end of the spring is suspended from a Brass chuck nut (pin vice) and the lower end is provided with a small pointer which moves over a vertical black painted aluminum pipe, on which scale is printed in colours.