This invention relates to a shock and impact testing apparatus for subjecting items under test, such as a motor vehicle crash sensor, to an acceleration pulse of a prescribed amplitude and shape, such as a half sine or haversine. The apparatus includes a stationary support providing a pivot point, a swivel arm mounted for rotational movement about the pivot point and an electric motor, arranged on the stationary support and mechanically coupled to the swivel arm, for rotating the swivel arm at a desired, prescribed speed. The arm has a free end for the attachment of the test object so that the test object is moved at the prescribed speed along a given path. A mechanical spring is arranged in this path for reversing the direction of motion of the test object, thereby imparting an acceleration pulse to the test object of a prescribed shape. The spring has a plurality of characteristic modes of vibration which provide different frequencies of vibration; however, the spring is constructed to reverse the direction of motion of the test object at substantially one frequency of vibration. The apparatus can also be used for subjecting a test object to a prescribed impact.