Why does the driver hit the ball farther than an iron?

Answer 1

The driver has:

* a longer shaft than an iron, so the clubhead speed is higher * lower loft, so the ball flies with more forward velocity and less height.

It's possible to take the lower loft too far, so that the ball travels a shorter distance. The optimum depends on the swing speed. It's somewhere between perhaps 7 degrees for really big hitters and maybe 13 degrees for a really slow swinger.