A 43-g ice cube floats in 155 g of water in a 100-g copper cup; all are at a temperature of 0°C. A piece of lead at 85°C is dropped into the cup, and the final equilibrium temperature is 12°C. What is the mass of the lead? (The heat of fusion and specific heat of water are 3.33 × 10⁵ J/kg and 4,186 J/kg × °C, respectively. The specific heat of lead and copper are 128 and 387 J/kg × °C, respectively.)
a) 21.0 g
b) 27.3 g
c) 32.9 g
d) 38.5 g
