[" a person breathes with maximal effort but with his nose and mouth closed,the alveolar "],[" ressure can be decreased to as low as? "]

One should breathe through the nose and not through the mouth. Explain.

Why is it advantageous to breathe through the nose than through the mouth?

A person opens his mouth on hearing a thunder in order to

The speed of rotation of a person with some weights in his hands and standing on a rotating platform increases as he draws his arms close to his chest.Why?Explain.

The pH of the mouth of a person is lower than 5.5. What changes will occur in his mouth ? How these changes can be controlled ? Write any two measures.

What did you feel after keeping your mouth and nose closed for so long ?

A person inhales to his maximum capacity and then he exhales also to his maximum. What is the volume of air thus breathed out?

Observe the picture given in Fig. 15.1 carefully and answer the following questions. (A) What is covering the nose and mouth of the police man ? (b) Why is he putting a cover on his nose? (C )Can you comment on air quality of the place shown in the Fig.15.1?