In this paper, the dynamic similarity of transient response caused by the collision between a sphere and a cantilever beam is theoretically investigated and the results are compared with the experiments. The theoretical analysis of transient response in a cantilever beam is conducted by the use of classical beam theory and with the aid of a Laplace transform which extends the fast Fourier transform to an inverse transform under the condition that the spheres strike cantilever beams at arbitrary points. The dynamic similarity of a cantilever beam is studied to use those results. In the experiment, the bending strain is measured by a strain gauge cemented to a bar of rectangular cross section of the model or the real thing. It is shown that the variation in bending strain of the model multiplied by the coefficient of similarity is in agreement with the real thing.