but that the temperature is forecast to rise to 25 degrees Celcius by 2pm when the race starts. It is your duty as Royal Engineer to set the tension of the wire, so that it will play just the right note when plucked at 2pm. To what tension should you set it? Hint: Assume that the expansion of the gold is unaffected by the presence of the wire. You do not need to know the length of the wire. You should do the Mastering Physics question with the brass rod and wires before this