Gold - 19. 32 Lead - 11. 3437 Silver - 10. 5020 Copper - 8. 5 to 8. 8 Steel - 7. 9 Iron - 7. 4 to 7. 7 Aluminium - 2. 7 Limestone 2. 6 to 2. 8 Glass - 2. 4 to 2. 8 Brick - 1. 4 to 2. 2 Concrete - 2. 2 to 2. 5 Ice - 0. 9 Wax - 0. 9 Pinewood - 0. 5 Mercury - 13. 543 Seawater - 1. 03 Water - 1. 0 Petrol - 0. 85

For example, if a cube has an acceleration of 1000 millimetres per second squared (always measure in millimetres) and the force exerted is 2 kilograms millimetres per second squared, then the cube must weigh 2 grams.