An iron wire of length 0.80m and linear mass density 6.4×10−4kg m−1 is stretched between two rigid supports.
(i) The wire is required to emit a note of frequency 256Hz when vibrating in its second harmonic. Calculate the tension that must be applied to the wire.
(ii) What tension would be needed if the same wire has to vibrate at 320Hz in its third harmonic while its length remains unchanged?