Wave from Helix (Slinky)

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.

Made of varnished wood with glass front and membrane suspended on cord for loading with sand to show positions of nodes and antinodes, overall length 760 mm.