When we add a certain amount of heat Q to a substance, the temperature of the substance increases by a [tex]\Delta T[/tex] given by
[tex]Q=m C_s \Delta T[/tex]
where m is the mass of the substance and Cs is the specific heat capacity of the substance.
By re-arranging the formula, we find
[tex]\Delta T = \frac{Q}{m C_s}= \frac{305.0 J}{(64.6 g)(0.128 J/gC)}=36.9 ^{\circ}C [/tex]
So, since the initial temperature of the metal is Ti=20 C, the final temperature is
[tex]T_f = T_i + 36.9 ^{\circ} C=20.0^{\circ} + 36.9^{\circ} C=56.9^{\circ}C[/tex]
