A wooden planed board 600mm x 75mm. The board is hinged at one end to a wooden base board and the angle of incline can be fixed in a number of positions by use of a moveable block. Also included is a reversible friction slider (100mm x 65mm) one side of which is cut so it has only half the area in contact with the plane to allow various dynamics situations to be explored.Complete with brass roller 75mm x 25mm and pulley wheel but WITHOUT masses or scale pan.