The required force to break a windshield depends on various factors, including the type of glass, its thickness, and the design and condition of the windshield. Generally, windshields are made of laminated safety glass, which is designed to withstand impacts and prevent shattering. It consists of two layers of glass with a layer of plastic (PVB) in between.
While it's difficult to provide an exact measurement of force required, it typically takes a significant impact to break a windshield. Forceful impacts from objects such as rocks, large hailstones, or a collision can cause a windshield to crack or shatter. However, it's important to note that intentionally damaging windshields or any other property is illegal and unsafe.
If you have concerns about a windshield or need repairs, it is advisable to consult with a professional technician or a reputable auto glass service for proper assessment and assistance.