Young Modulus of Copper
Physics TAS Young Modulus of Copper Objectives -Determine the Young modulus of copper by simple experiment -Study the relationship of strain and stress between elastic and plastic deformations of copper -Verify a wire will not return to its original length after certain extensions Preview Questions .Hooke's Law states that the elastic force is directly proportional to the extension (or compression) of the elastic body. A wire obeys Hooke's Law only if it is within its elastic limit. 2.Elastic deformation means a stretched wire will return to its natural length. If the wire is stretched beyond its elastic limit, it will not return to the original length and will make permanent extensions. This is called plastic deformation. 3.A longer wire will extend more than a shorter wire of the same cross-sectional area under the same applied force. 4.As in Q.3 , force constant can be easily affected by geometric factors such as length and cross sectional area. But the stiffness of materials depends on their Young modulus only, which is not affected by geometric factors. So force constant is not a good quantity to compare the stiffness of materials. Apparatus Copper wire ..................1 roll slotted mass with hanger 100g hangers ....................1 100g slotted mass .........~15
Why does the colour leak out of cooked beetroot?
Why does the colour leak out of cooked beetroot? Aim: To investigate the effect of temperature on membrane structure Introduction: I will be measuring the amount of light absorbed by the pigment in the beetroot, which will tell me how much dye has been released from the beetroot. My null hypothesis (H?) is: no matter what the temperature increase, the amount of dye being released from the beetroot will remain the same. My alternate hypothesis (H1) is: an increase in temperature will cause an increase in the amount of dye being released from the beetroot. Beetroot cells, like any other cells with membranes, have many types of cells with special functions. Some of these organelles are bounded by a single membrane, eg. vacuole, and some are bounded by two membranes e.g. nucleus, mitochondrion. Beetroot appears as a dark red/ purple colour and this is caused by the betalain pigment, which is contained within the vacuole of the beetroot cells. In order for the betalain to leave the cell it needs to pass through two different membranes; the membrane bounding the vacuole and the membrane enclosing the cell. An increase in temperature will damage and denature the membranes and cause the betalain to leak out. Variables: My independent variable is the temperature at which I am heating the beetroot, whilst my dependant variable is the amount of light absorbed by the pigment. I
