Question

Why is a thick glass more likely to crack than a thin glass when hot water is poured into it?

Answer 1

When you pour hot water inside a glass, the inner surface expands more compared to the outer surface due to difference in temperature.It happens because glass is a poor thermal conductor. This difference increases with increase in thickness because of gradient heat conduction. Due to this difference in expansion the glass develops cracks and eventually breaks.Whereas a thin glass will not have much difficulty in transferring heat from inner to outer walls so it does not crack.