posted by Bobby .
A paperweight, when weighed in air, has a weight of W = 6.8 N. When completely immersed in water, however, it has a weight of Win water = 4.3 N. Find the volume of the paperweight.
The 2.5 N reduction is due to buoyancy, which equals the paperweight volume multiplied by the weight density of water, which is 9810 N/m^3. Therefore
V = 2.5/9810 = 0.00025 m^3 = 250 cm^3