A 100g aluminum (c=900J/kg C) calorimeter contains 250 g of water (c = 4186J/kg C). The two substances are in thermal equilibrium at 10 degrees C. Two metallic blocks are placed in the water. One is a 50g piece of copper (c= 387J/kg C) at 80 degrees C. The other sample has a mass of 70g and is originally at a temperature of 100 degrees C. The entire system stabilizes at a temperature of 20 degrees C. Determine the specific heat of the unknown second sample.