A 550- N person empties her lungs as much as possible and is then completely immersed in water of density 1000 kg/m³ while suspended from a harness connected to a spring scale.The spring scale reads now 21.2 N.What is her density? A)1050 kg/m³ B)1040 kg/m³ C)1030 kg/m³ D)960 kg/m³ E)56.1 kg/m³

Question

Quizplus · Accepted Answer

The apparent weight of the person when submerged is the actual weight minus the buoyant force. The buoyant force equals the weight of the displaced water, which can be found from the difference in readings (550 N - 21.2 N = 528.8 N). The volume of the person is equal to the volume of water displaced, which can be found using the buoyant force and the density of water (528.8 N / (1000 kg/m^3 * 9.8 m/s^2)). The density of the person is then the actual weight divided by this volume, which gives approximately 1040 kg/m^3.

A 550- N Person Empties Her Lungs as Much as Possible