Consider that the "hot" silver will give up heat and reduce temperature while the aluminum cup, copper stir and water will aborb this heat (assume no heat is lost from this system). Use the formula for the change of heat delta Q = Mass*Specific Heat*delta T. Specific heats are found from any table of values and they are Water = 1, Copper = .0973, Aluminum = .215 and Silver = .0558 (all dimensionally cal/gm-K). The delta T for the water, aluminum and copper = 32-27 = 5 degrees C (same in K). The delta T for the Silver = 32-85=-53 C. Now write an equation describing the balance of heat flowing from the hot silver into the cool water, copper and aluminum. 0= 435*.0558*(-53)+225*1*5+40*.0973*5+ mAl*.215*5. Solve to find mAl = 131.5 grams.
