<span>Energy = Mass * heat capacity * temperature change so, </span>The energy added is 435 J and the temperature has to increase since the energy is added.
<span>435 J = 10.0 g * 0.89 J/gC * temperature change </span>
<span>Temperature change = 48.9 C </span>
<span>The initial temperature is 25.0 C, the final temperature is 25.0 C + 48.9 C = 73.9 C.</span>
When you pull a rubber band there is elastic potential energy stored in the rubber band but once you let go of either side the EPE turns into Kinetic Energy.