One way to estimate muscle mass is to determine a person’s density. You fill a large container with fresh water (of density 1000 kg/m3). Standing on a force plate outside of the water, your classmate weighs 550 N. She empties her lungs as much as possible and is then completely immersed in water while suspended from a harness attached to a force sensor. It reads 21.2 N when she is fully submerged and still. What is her density? Would she float or sink in salt water (density 1030 kg/m3)