Why are glass windows possible to crack in very cold region?

because normal glass windows contain microscopic air bubbles with expand while it is heated or cooled and starts cracking from edge

a charge 3q is at the origin, and a charge −2q is on the positive x axis at x=a. part a where on the x-axis would you place a third charge so it would experience no net electric force? enter an expression for the exact answer, which will involve a square-root sign. (do not enter an approximate decimal answer.)