compared with or to
A woman is physically weaker compared with/to a man

Question

Answer

To compare to is to point out or imply resemblances between objects regarded as essentially of a different order;

to compare with is mainly to point out differences between objects regarded as essentially of the same order.

--- So: "Women are physicially weaker compared to men."

Source: http://www.dailywritingtips.com/compared-to-or-compared-with/