Question

Blacksmiths use the principle of thermal expansion to fix the iron rim onto the wooden wheel of a bullock cart. Why?

Answer 1

Dear Student,

Thermal expansion of a matter is the change in its volume in response of a change in surrounding temperature. In case of a solid body, this change can be also linear and superficial, depending on overall dimensions of the body.

As we know that metals expand on heating and contracts on cooling. The iron rim used is smaller when compared to wooden wheel. The irom rim is heated so that it expands and when the size of the ring is larger than the wooden wheel, then the iron rim is slipped into the wooden wheel. When the iron rim cools, it contracts and hold wooden wheel tighter and gets fitted to wooden wheel.

Regard