Note:  Do not rely on this information. It is very old.


Blow, in Dynamics, means the sudden change of motion given to a body by the impact of another, of a mallet on a chisel for example. It is measured by the total momentum produced, and the effect is equivalent to that of a large force acting for a very brief interval. The average force during the blow is found by dividing the momentum produced by the short interval of time during which the impact lasts. The duration of the blow depends on the shape, mass, and material of the two bodies.