question_answer

Explain the following observations very briefly.

(a)  A firki does not rotate in a closed area.

(b) The arrow of weather cock points towards a particular direction at a particular moment.

(c)  An empty glass in fact is not empty.

(d) Breathing through mouth may harm you.

Answer:

(a) A firki does not rotate in a closed area due to no air movement.

(b) The arrow of weather cock points towards a particular direction at a particular moment as it shows the direction of movement of air.

(c) An empty glass in fact is not empty because it is filled with air.

(d) Breathing through mouth may harm us because dust particles present in air may also get inhaled which are harmful.