INERTIA BALANCE FOR INVESTIGATING THE NATURE OF MASS AND THE DISTINCTION BETWEEN MASS AND WEIGHT. TWO METAL TRAYS 130 X 55 X 23 MM ARE JOINED TOGETHER WITH TWO SPRING STEEL STRIPS OF 10 MM WIDTH , THE DISTANCE BETWEEN THE TRAYS BEING 215 MM . ONE TRAY IS DRILLED TO ACCEPT 3 EQUAL CYLINDRICAL MASSES. THE OTHER TRAY CAN BE CLAMPED TO A BENCH HORIZONTALLY OR VERTICALLY. COMPLETE WITH 3 MASSES AND A G-CLAMP. Qty :