when heat is applied to a metal with a hole in it
? why does the radius of hole increase?

Question

when heat is applied to a metal with a hole in it 
? why does the radius of hole increase?

anonymous · Answer

This short answer I'm presenting first is a little unscientific, but: the metal body does not know it has a hole in it.

All dimensions will grow due to thermal expansion, including the diameter of the hole.

You can also think that if you have a metal body and you cut a piece away from it (so that you have a piece with hole and a cylinder [which was removed from the hole]), the cylinder expands due to heating, was it inside the hole or not.

This is a simple thing but hard to explain, if someone can explain better please do it.

preetha · Answer

The atomic level answer would be that heat causes expansion and all the atoms move apart due to increased thermal activity.

anonymous · Answer

but if thermal expansion occurs it  must take place in all possible directions and the change in radius then will unprdictable