The linear expansion coefcient a for Al is 23*10'5/DC. A rod with a crosssections area of 1 cm2 and a length L = 113 cm is heated from 20 C to 131 c'C. What is its change in in its length, AL, in mm? Enter a number with 2 digits behind the decimal point. In a popular classroom demonstration, a cotton ball is placed in the bottom of a strong test tube. A plunger ts inside the tube and it makes an air-tight seal. It is then pushed down very rapidly, and the cotton ashes and burns. This happens because 0 friction between the plunger and the tube ignited the cotton. O when the air gets compressed its temperature increases. 0 cotton contains a pressure-sensitive substance that burns upon impact. 0 This is one of those demos that nobody understands