Question

In a disaster at sea, life vests (also called personal floatation devices, or PFDs) can save lives. If you were to design a PFD, what material would you use? Why? Be sure to use the word 'density' in your explanation.

a) Foam with low density, as it provides buoyancy without adding excessive weight.
b) Lead, due to its high density, ensuring effective flotation.
c) Cotton fabric, known for its low density and water-resistant properties.
d) Steel, for its high density and durability in challenging conditions.

Answer 1

Foam with a low density is the most suitable material for a personal floatation device because it is less dense than water, helping to ensure buoyancy and effective flotation.

Step-by-step explanation:

When designing a personal floatation device (PFD), the material chosen should enable the device to keep an individual afloat in water. Hence, the most suitable material would be foam with a low density, as its density is less than that of water, providing buoyancy without adding excessive weight. The concept of density is critical in this context because a material with a lower density than the water will result in the PFD floating, thereby saving lives during a disaster at sea. Materials such as lead, cotton fabric, and steel are not appropriate choices for a PFD because of their high densities, which would cause them to sink when placed in water, thus failing to serve the crucial function of a life vest.