Spencer Heath Archive

Item 835

Recollected by Spencer MacCallum following conversation with Heath

February 1956

Dyne is the inertia of 1 gram accelerated to a speed of 1 centimeter per second during one second. The mean velocity is ½ centimeter per second. So the distance covered is ½ centimeter. Hence the 2 in the formula, E = mv²/2, which is not a quantity of work but a rate of action.

The particular rate at which it would apply if it met a mass or force or inertia equal to itself.