2.What causes muscular fatigue and pain when a person undergoes
strenuous physical activity like cycling, running, heavy weight lifting?
3. When you breathe out some air through your mouth onto the surface on a
clean mirror, why does the surface of mirror becomes cloudy?
please answer fast tommorow is my exam.. please answer faster
Answers
Accumulation of lactic acid in the muscle due to lack of oxygen causes muscular fatigue and pain when a person undergoes strenuous physical activity like cycling, running, heavy weight lifting.
The internal temperature of the body is higher than the external temperature thus the air we breathe out is at a higher temperature that the surface of the glass. When this warm air strikes the colder surface of the mirror the water vapor present in it condenses on it and makes it cloudy.
Explanation:
- During strenous exercise the rate of consumption of oxygen by muscle cell exceeds the amount of oxygen available to them. This results in conversion of pyruvate into lactic acid.
- This condition is called oxygen debt.
- The lactic acid accumulates in the muscle, causing pain and fatigue.
- On taking rest the lactic acid decomposes and the pain is relieved.
The normal body temperature of a person is 37 degree Celsius While the surface of the mirror is at a lower temperature.
When the water vapor present in expired air strikes the surface of mirror its molecules loses kinetic energy and condenses on the surface of mirror making it cloudy.