Wave from Helix

Simple type model, it comprises a wooden board 700 x 90 mm (L x W) on four feet, fitted with two steel wires about 0.3mm x 1m (dia x length). At one end of base there are two 50 N spring balances with hooks and at the other end are two wrest pins, supplied complete with three bridges, one large, to span both wires and two small bridges for individual wires, two steel wires 0.3 mm dia. x 1 meter long.

To determine the standing longitudinal waves in column of air and velocity of sound in air, it comprises of a glass tube approx 1.2 meter length and 34 mm diameter. There is a tightly fitting but adjustable piston on a 390 mm long rod at one end of the glass tube. A loose fitting piston attached to a 1.2 meter long sounding rod at the other end of the glass tube, fitted on a wooden base.