Bibliography is essential in determining its content. I hope this helped
Your heart rate before exercising would probably be the at rest rate of say about 50-60 beats per minute whereas immediately after exercise it could easily be say 115-130 and depending on age there is an optimum heart rate for each age range which decreases somewhat with age. Timing for a full minute your heart rate is best as it will give the actual count whereas if you just do it for 10 seconds and then multply by 6 it would assume it will be consistent whereas it could decrease during the minute so the actual measured count for a full minute is more accurate.
It has a huge roll and lol go learn bio
If I recall correctly, I was taught:
The particles in the air (dust, smoke, etc.) increase in density the farther you look. Causing a "fog" effect as you look across large distances. Including shore to shore of an ocean.