Why do violin bows make a pitch when rubbed against a violin string instead of just a rubbing sound?

Question

Why do violin bows make a pitch when rubbed against a violin string instead of just a rubbing sound?

In: Physics

Answer 1

The way a bow works is straddling the line of grippiness with the string so that pulling the bow causes the string to be pulled along with it, up to the point where the tension in the string lets it slip back, where it grips and pulls again, with the process happening hundreds of times a second.

You’d get a rubbing sound (or probably a screech) if the bow wasn’t gripping the string enough, and was allowed to slide more freely.