A heater of resistance 1.6 ohms is used to heat 10 kg of water in a copper calorimeter.

Step 1: Identify the given values for part 5a.

• Voltage of heater $V = 1.6 \, \text{V}$
• Current through heater $I = 0.1 \, \text{A}$
• Time duration $t = 15 \, \text{min} = 15 \times 60 = 900 \, \text{s}$
• Mass of copper calorimeter $m_c = 1.5 \, \text{kg}$
• Mass of water in calorimeter $m_w = 10 \, \text{kg}$
• Initial temperature of calorimeter and water $T_1 = 30^\circ \text{C}$
• Mass of ice added