GP Industries Ambala Cantt, Haryana

For demonstrating longitudinal and transverse motion, consisting of 18 acentric Aluminium disc supporting a series of metal rods. On revolving the handle, transverse waves are obtained with bent, straight rods. Complete on wooden box.

The free fall apparatus comprises two units, each of which is mounted on a plastic base, which can be clamped on a 13mm diameter retort rod. Connections are brought out to 4mm sockets. The solenoid unit has a mumetal core, which ensures prompt release of the ball on de-energising. The gate switch unit comprises a hinged steel plate, which is held against an adjustable contact by means of a small permanent magnet, so that, by proper adjustment, the plates fall away promptly at the impact of the falling ball.

The trolley consists of a rectangular wooden body carried upon three low-friction plastic wheels and is supplied with one strong spring plunger and three dowel pegs. Several trolleys may be stacked on top of each other and are held in position by holes drilled underneath which fit over dowel rods placed in corresponding holes in the upper surface of the lower trolley. This enables the effective mass of a trolley to be increased to two or three times its basic mass. Sufficient space is provided on the flat of the trolley for the addition of heavy loads