FYKOS Year 26 Series 4 Problem 4 — Hit it with a hammer · FYKOS 26 #26.4.4
Physics · mechanics
Problem
Imagine hitting one end of an iron rod and observing the resulting sound waves. Describe (using drawings) the time dependence of the wavefronts in the plane of the rod. We are especially interested in what the wavefronts would look like at two particular moments. The first one is the time when the sound wave reaches the other end of the rod, and the second one is the moment the wave reaches the original end of the rod after reflecting at the other end. Do not forget to describe how did you construct your drawings. You can assume that there are only longitudinal oscillations of the rod, and that its diameter is negligable compared to its length. The ratio of the speed of sound in the rod and in the air is β=vrod⁄vair≈10.