The apparatus consists of an electromagnet housed in a plastic molded case with connections for an external timer, with a heavy steel sphere, and a platform unit. For determination of 'g' (the gravitational acceleration) by free fall method. The apparatus consists of an electromagnet which is housed in a plastic molded case with 4mm socket connections provided to energize the magnet and another pair of sockets for connection to a timer in use. To perform the experiment, an electromagnet is energized and a metal sphere is attached. As soon as the power to the electromagnet is switched off the sphere falls and the unit activates the timer. When the sphere hits the platform, which is connected to a micro switch, the timer stops and the time of fall can be determined.

• Unit conveniently attaches to all commonly used stands (stand not supplied)