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Let’s first take a balance that works as a lever. In this experiment we will use the illustrious crown, a golden and silver bullion with same weights. We will also use a random weight which will hold the crown in balanc on the other side. Firstly we put the golden bullion on the balance, on the other side we put the random weight and balance the mechanism. We mark the place of the weight on the left side. We do the same process for silver bullion. Since the silver bullion has a lower density than gold bullion, the place that we mark on the left of the balance will be closer to the centre of the balance. Now we start the actual process. We put the crown on the right of the balance with a beaker filled with water. We mark the place where the mechanism is in balance. If the crown was actually made up of gold, the mark that we just put on the balance will be closer to that we put for the golden bullion. If the crown was made up of silver, the mark will be closer to that for silver bullion. If there is little amount of silver in the golden crown, the last mark we put on will be between the two marks for golden and silver bullions. The best thing in Galileo’s method is that it gives an idea for the ratio of gold-silver in the crown. The closer mark for the crown to the mark for golden bullion, the higher amount of gold in the crown. In this case we find out the ratio of silver-gold in the crown. You can find the detailed numerical values in Galileo’s book, La Bilancetta. If we want only to find out whether the crown was made up of gold, we could do this easily by using Galileo’s idea. We can put the crown on one side of the balance, and the golden bullion on the other side with a same weight. We both put those weights in beaker filled with water. If the crown is only made up of gold, the balance is in equilibrium. If there is silver mixed in the crown, the crown will go up in the balance. IMPORTANCE OF BIODISEL Biodiesel is a domestic, clean burning fuel for diesel engines can be made from animal and vegetable fats and oils. Unlike petroleum-based diesel, biodiesel is a renewable source of fuel because it can be used more than one time. Also, biodiesel is better to conventional diesel in many ways. Biodiesel is a non-toxic (not poisonous or not containing poisonous substances) and biodegradable (able to decay naturally and in a way that is not harmful) fuel. Biodiesel has some essential properties as fuel that the viscosity (a viscous liquid is thick and sticky and does not flow easily) is important because it influences the separation of atoms of the fuel being placed into the engine combustion chamber. For complete combustion to happen, a small fuel drop is needed. The biodiesel fuel property of having the viscosity much closer to diesel fuel than vegetable oil helps to create lower drop which is help to keep burner clean. CHEMISTRY DEPARTMENT References: 1. https://www.math.nyu.edu/~crorres/Archimedes/ 2. Crown/CrownIntro.html 3. https://www.math.nyu.edu/~crorres/Archimedes/ Crown/bilancetta.html http://www.longlongtimeago.com/once-upona-time/great-discoveries/eureka-the-story-ofarchimedes-and-the-golden-crown/ Ozan KIRDAR 11-B THE CLAPPER 2015 - 2016 55