Question

Hydrostatic weighing uses water displacement to measure body volume.
True
False

Answer 1

The statement is true; hydrostatic weighing uses water displacement to measure body volume, which is a key factor in determining body density and calculating body fat percentage.

Step-by-step explanation:

Hydrostatic weighing indeed uses water displacement to measure body volume. This method is part of body density determination and is a technique to calculate a person's percent body fat. During the process, a subject is first weighed in air and then weighed again while completely submerged in a hydrostatic weighing device. To facilitate submersion, the individual must exhale completely to empty their lungs and hold a metal weight. Corrections are then made for the residual air in the lungs and the metal weight. This corrected submerged weight, along with the out-of-water weight and pinch tests of strategic fatty areas, are used for the body fat calculation. The principles behind hydrostatic weighing include Archimedes' principle, which states that the buoyant force on an object is equal to the weight of the fluid displaced by the object, causing the object to have an apparent weight loss underwater equal to the weight of the fluid displaced.

Answer 2

The statement is false because hydrostatic weighing does not use water displacement to measure body volume.

Explanation:

Hydrostatic weighing, also known as underwater weighing, is a method used to determine body density and subsequently calculate body fat percentage. It does not involve water displacement in the way implied by the statement. Instead, the individual is submerged in water, and their body density is calculated based on the buoyancy principle. Archimedes' principle states that the buoyant force acting on a submerged object is equal to the weight of the fluid displaced by the object. In the context of hydrostatic weighing, the weight of the water displaced by the submerged body is used to calculate body density.

The process involves measuring the weight of the individual outside the water and then again while submerged. The difference in weight, combined with the density of water, allows the calculation of body volume. Once the body volume is known, body density can be determined, and subsequently, body fat percentage can be calculated using established formulas. It's a precise method that takes advantage of the relationship between buoyancy and body density, providing an accurate assessment of body composition.

In summary, hydrostatic weighing relies on principles of fluid mechanics and buoyancy rather than water displacement to measure body volume, making the statement false in the context of this body composition assessment method.