On mountain tops, we breathe more and our ears tend to pop.Why?

Why do we sweat more in a humid day ?

Why should we breathe all the time ?

Explain why, despite good rains, we are not able to meet the demand for water of all the people in our country.

Why do we call our heart myogenic?

Why do we pass more urine during winter and wet seasons ?

We do not sense any pain when we clip our nails or cut our hair. Why?

If we put a cardboard (say 20 cm xx 20 cm) between a light source and our eyes, we can't see the light. But when we put the same cardboard between a sound source and our ear, we hear the sound almost clearly, Explain.

Why do we pass more urine in wet and cold season?

(a) When we put our ear to a railway line, we can hear the sound of an approaching train even when the train is far off but its sound cannot be heared through the air. Why? (b) How could you convince a small child that when you speak, it is not necessary for air to travel from your mouth to the ear of a listener?