Why don't action and reaction forces on a person swimming in water cancel each other out

They Act on Different Objects

Explanation:

Newton's Third law of motion states that action and reaction are equal and opposite. The action and reaction forces in of Newton's Third Law -works on different objects.

In Real life examples, or situations  like, A textbook lying on  a table  ever, A cup pressing down on the table, or a table pressing up on an iron, these forces in this cases,  are balanced by extra or additional  forces, and at times, they are not.

Most importantly  action and reaction forces from Newton's Third Law of motion act on different objects, But  forces working  on the same object or entity  may cancel  out this is from( Newton's Second Law), So long as the sum of their is considered  to be zero.

a high pressure system is a dense air mass that is usually cooler and drier than the surrounding air. a low pressure system is a less dense air mass that is usually wetter and warmer than the surrounding air.

in general, areas that experience high atmospheric pressure also experience fair weather. low pressure systems can cause the formation of clouds and storms. air usually flows from areas of high pressure to areas of low pressure..

no sign of dia of fuel cell