If a ring of iron is heated then what happens of the hole of the ring?
1 Answer
Mar 10, 2018
Your first thought would be that the hole becomes smaller, because the ring becomes thicker.
Explanation:
But that is not what happens. OK, the ring gets thicker, but also larger.
Think of looking at the ring through a slightly magnifying glass (say with a magnification of 1.01x, which will add 1% to all dimensions.
Then everything will be enlarged: the outside diameter, the thickness, but also the diameter of the hole.
In my physics lab we have a solid ball that (at normal room temperature) will just fit through a ring. We heat the ball, and it expands, so it will not fit through the ring anymore. We now let the ball rest on the ring, so heat is tranferred and the ring heats up.
After a while they reach the same temperature and the ball falls through.
