Burning wood frequently pops and cracklings • The ground why a combustion wood dads and cracklings is because of two things. First is due to the belongings of conductivity. Wood is non a really good music director of heat. Second ground is due to thermic enlargement. An addition in temperature in any affair consequences to a alteration in the volumetric belongings of affair. Wood expands when heated or in this instance burned. The firing portion of the wood is spread outing but since wood is non a good music director of heat. the other parts of the wood that is non firing merely experiences a really small sum of addition in temperature.
Therefore. the enlargement of the unburned parts of the wood is really minimum or negligible. The firing portion of the wood continues to spread out and exercise force per unit area on to the other unburned parts of the wood. When the wood could non incorporate the force per unit area. the burning/expanding portion clefts which makes a popping sound. B. You can non do a three-minute egg a two-minute egg in boiling H2O by turning up the heat • The construct behind this is heat transportation from the boiling H2O to the egg.
Even if we try to turn up the heat. the boiling H2O would still hold a temperature of 100oC. since it is already the boiling point of H2O at room temperature and changeless air force per unit area. The heat being transferred to the egg is relative to the difference in temperature between the egg and the surrounding. which is the boiling H2O. Since the temperature of the H2O stays at 100oC. the difference between the egg and the H2O would non increase. therefore would besides non increase the sum of heat being transferred. 2. Concept behind plane mirrors
We can utilize ray following method to analyse and work out this job. Since plane mirrors have a magnification equal to 1. the size of the image is equal to the size of the existent object. In figure 1. the ruddy broken line is the perpendicular line at the point of contemplation. The angle of the incident light beam is equal to the angle of the reflected light beam. Since the length of the incident beam and the reflected beam is equal. we can state that the image that can be seen is equal to twice the tallness of the mirror. which equates to 2m*2=4m.
So this means that the adult male can see 4/6 or 66. 67 % of his image. In figure 2. we can see that even though the adult male moved an extra 5ft. off from the mirror. the sum of the image he can see is still 66. 67 % . 3. Sound waves a. The equation v= ? f holds true for sound moving ridges. The speed V of the sound is changeless when propagating in air. So this means that sounds with different frequences will go at the same velocity in air. but with different wavelengths? . Thus both sounds will make your ear at the same clip.