Why Are Men Physically Stronger Than Women?

It is just the way god created us. Man was created to be the protector and the provider of the woman.

Yes the average man is stronger than the average women.  There are some women that are stronger than men but the strongest women is not even close to the strongest man.

Testosterone levels in men are higher than in woman, because of this the average man is of larger built than the average woman. Thus the average man (more muscle mass) is stronger. Estrogen on the other hand produces a smaller overall frame (i.e the average woman is of smaller frame, thus less muscle mass = less strength), however pound for pound a woman is stronger than a man. This is because of the effects the aforementioned hormones have of the human body.

The aforementioned is a general statement. Read up on the effects of Hormones on the body, locomotion, and physiology to get a better grasp.

Mostly because of  Physiological reasons, and in the history, men always do things which need power and so gradually become stronger and stronger. As we know, men take lots of time for sporting.