Assume we have the metal bar of length L0 metres at temperature T0 in degrees celsius. When bar is heated or cooled, length of bar changes. Amount that length changes is proportional to product of temperature change and original length of bar L0. Let a be proportionality constant of the change where units for a is measured in m=m/m°C (metres per metres degree celsius). Write the expression for length L of metal bar as the function of temperature T. Draw the sketch of graph of function, labeling the point where T= 0.