On a very cold morning, Boojho and Paheli were talking with each other as they walked down to their school. They observed that the air coming out of their mouth looked like smoke. They were amused and wondered how it happened. Help them find the answer.
Actually it is not the smoke that comes from mouth in the mornings. Moreover smoke does not come in every morning. Only in winter season that too when the climate is too cold, smoke comes from the mouth when the person speaks. When we speak, we undergo exhalation process in the breathing technique. That means along with the words, air comes out through the mouth from lungs. In any season, temperature inside the body of human being would be stable at 98.4 degrees Fahrenheit i.e. thirty seven degrees centigrade. In winter season, the air that comes out of our mouth would contain water vapor. Since the temperature outside the body is extreme colder, much of the water vapor present in it transforms from gaseous form into liquid form. In that process, particles of water vapor transform into a rain of tiny water droplets. When sunlight falls on those water droplets, it gets scattered in all directions. Hence it appears as smoke coming from mouth. The same is the reason for the smoke appearing to be coming from an ice piece and smoke appearing back to the jet plane in its path.