Ideal apparatus to study the concept of motion on an inclined surface and its relation to the friction. Consists of wooden base board with glass/sun-mica top which is hinged on a base board measuring 45 x 10 cm. The pulley is attached to one end of the planed section upper board which can be clamped at any angle from 0-45°, upper board dimensions 600 x 100 mm. A graduated metal arc enables the user to read the angle (in degrees) and the height (in cm) of the force triangle directly from the scale. Supplied with roller and pan, but without weight set.