A long, slender metal rod is held firmly at one end while the free end is struck sharply with a wooden hammer in an otherwise quiet room.
(i) Identify the type of mechanical wave that travels along the length of the metal rod after the blow.
(ii) Explain, with reference to particle motion, why a listener who places an ear in contact with the far end of the rod hears the sound sooner than another listener standing in air a short distance away from the rod.
(iii) Draw a neat, labelled sketch showing compressions and rarefactions (or crests and troughs, as applicable) for the wave in the rod.
(iv) If the rod were instead replaced with a tightly stretched metal wire struck in the same manner, what change, if any, would occur in the wave type generated along it? Give reason for your answer.