When two opposing powers are equal, there is no motion, and when one power “overcomes” the other, the body moves until it suffers “exhaustion” (kalal), because any body moved “violently” creates a contrary power stronger than the one imposed by the mover, and also because the imposed force becomes “exhausted”. The moving power is also subject to time and distance factors and the mobile can offer almost no resistance, so that the absolute terms of proportionality do not apply.