a $49\mathrm{.}1$mm diameter copper rod is resuced to a $38\mathrm{.}3$mm diameter then reduced again to a final diameter of $25\mathrm{.}4$mm in a second case the $49\mathrm{.}1$ mm diameter rod is reduced in one step from $49\mathrm{.}1$mm to $25\mathrm{.}4$mm calculate the CW for the first case