The splined ends and gears attached to the a992 steel shaft (g = 75*109) are subjected to the torques shown where t=300

The rocks expand when there hot/warm  and contract when they are cold.

The radiation of the fire causes the saucepan to heat up. the conduction of the saucepan then to distribute the heat over the saucepan and to give heat to the water. the convection of the water distributing the heat within the water, till all the water is boiling