Question

It is a hot summer day, Priyanshi and Ali are wearing cotton and nylon clothes respectively. Who do you think would be more comfortable and why?

NCERT Class IX
Sciences - Exemplar Problems

Chapter 1. Matter in our Surroundings

Answer 1

Sweating is a natural mechanism by which our body regulates internal body temperature.
During summer, we sweat a lot. And cotton cloth is a good absorber of sweat and on EVAPORATION of sweat we feel cool. Whereas nylon cloth does not absorb The water.
So If one wears cotton clothes during summer and as sweat evaporates we feel cool. Moreover area of surface of clothes worn by us is more .so rate of EVAPORATION further increases and results in cooling.

Thus,
Priyanshi who is wearing cotton would be more comfortable .

Answer 2

Answer:- Priyanshi would be more comfortable.

Explanation:- The reason is that we get a lot of sweat on our body in a hot summer day.

Cotton being a good absorber of water, absorbs sweat from the body and provides larger surface area for evaporation which causes more cooling effect. Nylon does not absorb sweat, so the sweat does not evaporate and Ali would feel uncomfortable.