The mechanical behaviours of a bar of finite length in high velocity tension are analyzed using characteristics based upon strain rate independent theory, assuming rigid- and elastic-linearly work hardening material properties. In these cases, the solutions on the relation of breaking strain ε_b versus tensile velocity V_1 can be obtained for the all range of V_1, though it can not be obtained in the case of a bar of semi-infinite length. Critical impact velocity exists for finite bar also, and coincides with the value for infinite bar. The relations of ε_b versus V_1 are of saw-teeth. These theoretical results seem valuable for the appreciation of experimental results.