Examveda

What is the principle of a ''Life Jacket"?

A. It provides oxygen to a drowning person

B. It increases the volume of the person to keep him afloat

C. It decreases the volume of the person to keep him afloat

D. The person can sit on it like a raft

Answer: Option B

Solution (By Examveda Team)

The upward-pushing force that keeps things afloat is called buoyancy. For an object to float it must be able to equal its own weight by displacing enough water. A life jacket is mainly filled with gas which has a very low mass. As such when worn by a person, it acts to significantly increase their volume for only a very small increase in their mass. This means that they have a lower density than normal which increases their buoyancy and helps them to float.

This Question Belongs to General Knowledge >> Physics

Join The Discussion

Related Questions on Physics

Radiocarbon is produced in the atmosphere as a result of

A. Collision between fast neutrons and nitrogen nuclei present in the atmosphere.

B. Action of ultraviolet light from the sun on atmospheric oxygen.

C. Action of solar radiations particularly cosmic rays on carbon dioxide present in the atmosphere.

D. Lightning discharge in atmosphere.