To demonstrate that gravitational acceleration down an incline is independent of the falling mass. The two-wheeled trolley runs across the room on an inclined overhead cable. Mounting hardware, 10.8 m of cable, and full operating instructions are supplied with the unit. Size is To demonstrate that gravitational acceleration down an incline is independent of the falling mass. The two-wheeled trolley runs across the room on an inclined overhead cable. Mounting hardware, 10.8 m of cable, and full operating instructions are supplied with the unit. Size is 15 x 10 cm. Mass set and hanger are not supplied with apparatus. The mass set and hanger are not supplied with apparatus.