Question
What type of clothes should we wear in summer? Why?
✓
Answer
We should wear cotton clothes in hot summer days because we perspire more through the pores of the skin during such days. Since, sweat is mainly water and cotton clothes are good absorber of water, they absorb the sweat quickly and expose it to the atmosphere for evaporation. The evaporation of sweat from the cotton clothes takes the latent heat of vaporization from our skin hence the skin loses heat and makes us feel cool and comfortable.
Need a full question paper?
Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.
Explore more
Similar questions
A body of mass 2kg is at rest. What should be the magnitude of force which will make the body move with a speed of 30m/s at the end of 1s?
How is it that bats are able to fly at night without colliding with other objects?
Why do we hear more clearly in a room with curtains then a room withour curtains?
The longitudinal waves travel in a coiled spring at a rate of 4m/s. The distance between two consecutive compressions is 20cm. Find:
- Wavelength of the wave.
- Frequency of the wave.
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 heard through the air. Why?
A heavy car $A$ of mass $2000\ kg$ travelling at 10m/s has a head-on collision with a sports car $B$ of mass $500\ kg$. If both cars stop dead on colliding, what was the velocity of car $B$?
→What is meant by the term ‘acceleration’ State the SI unit of acceleration.
The mass of sun is $2 \times 10^{30}\ kg$ and the mass of earth is $6 \times 10^{24}\ kg$. If the average distance between the sun and the earth be $1.5 \times 10^8\ km$, calculate the force of gravitation between them.
→Which method is better for recovering sugar from sugar solution: evaporation or crystallization? Give reason for your answer.
Given alongside is the velocity-tine graph for a moving body:
Find:
Find:
- Velocity of the body at point C.
- Acceleration acting on the body between A and B.
- Acceleration acting on the body between B and C.