When you step from the shade into the sunlight, the Sun’s heat is as evident as the heat from hot coals in a fireplace in an otherwise cold room. You feel the Sun’s heat not because of its high temperature (higher temperatures can be found in some welder’s torches), but because the Sun is big. Which do you estimate is larger, the Sun’s radius or the distance between the Moon and Earth? Check your answer in the list of physical data on the inside back cover. Do you find your answer surprising?
Sunlight The main methods of heat transfer is : 1, Radiation, 2, Convection and, 3, Conduction. The above figure explain the how the heat transfer into different method. Radiation: The main example of radiation is Sunlight. When you are out in the sun you get warm because the sun is shining on you and absorb heat from the light hitting you. You get sunburned heat if you absorb too much ultraviolet radiation which is energetic enough to damage skin cells. We don’t notice radiation unless we near something hot because most everything is at room temperature. Convection: Example of convection is w ind chill. The wind blowing on you causes more heat to be transferred from you to the air than if the air is still. Conduction: In conduction, imagine touching a piece of metal at room temperature. It feels cool, because heat is easily transferred from you to the metal. If you touch plastic material it doesn’t feel as cool because, even though it is at the same temperature. You feel the Sun’s heat not because of its high temperature If we say that if we lose heat from our bodies quickly that our environment is ‘cold’. If we get heated by what around us then it is ‘hot’, If we jump into ocean, it feels cool because of water is colder than our bodies and because water conducts heat away from us very easily. Which do you estimate is larger, the Sun’s radius or the distance between the Moon and Earth The sun radius is nearly twice the distance between the earth and the moon. The sun is almost twice as hot as the coals in a fireplace. The strength of the heat we feel has nothing to do with either the distance, or the size, or the temperature of the sun. The sun is only twices as far from the earth as the moon is The sun radius is 7×10 m. , So the distance between the earth and the moon is about 4×10 m. 8 The sun is much hotter than the coals and much distance from the earth and the moon is.