This note reports on simple equations that can be used to interpret the behaviour of structural members struck by impact loads as used in a simple undergraduate laboratory exercise. The application of these equations is illustrated for some test results on a long vertical thin-walled top-hat section struck axially by a large mass at one end and supported on a rigid foundation at the other end. This is a particularly simple experimental arrangement, which is suitable for illustrating various features of the mass impact loading of a structural member to undergraduates. It is possible to predict various characteristics of the structural response with the aid of these equations and the minimum of instrumentation.