Isn't 90 degrees is straight up? Perpendicular to the ground. Car is not moving. The hailstone wouldn't even hit it. We must not have have the same understanding as to the angle of the dangle. I'm interpreting 15 degrees as almost flat. Say at 9:30 o'clock. 30 degrees at about 10:00 o'clock.
Originally Posted by spasm3
15 degree. That angle absorbs less energy and allows the hailstone to continue moving imparting less energy to the glass. Seems to me the closer you get to 90 degrees, the more energy is absorbed by the glass.