 temperatur chart induct constant temperatur heat temperatur chart induct constant temperatur heat chart present determin complet temperatur histor sphere cylind plate valu dimensionless time ratio greater 0 2 heat equat reduc simpl form shape chart temperatur posit heat cool bodi plot usual simpl heat cool chart determin temperatur heat time bodi heat constant rate heat gener surfac induct heat final dimension chart find heat time short cylind elimin trial-and-error solut heat time on-dimension chart 