**Thermal Conductivity – Practice**

**Questions:**

1) What is the rate that energy is transferred through a 50cm long piece of silver with a cross-sectional area of 0.05m^{2} with one end at 20°C and the other end at 80°C? (Thermal conductivity, k, of silver = 420 Wm^{–}^{1}K^{–}^{1})

2) How much energy is transferred along a 10cm long piece of copper in 30 seconds if it has a cross-sectional area of 0.04m^{2} with one end at 20°C and the other end at 50°C? (Thermal conductivity, k, of copper = 386 Wm^{–}^{1}K^{–}^{1})

3) Calculate the rate of energy transfer across a 1m^{2} section of a timber home that is 10cm thick. The outside temperature is 5°C and the inside temperature is 21°C. (Thermal conductivity, k, of wood = 0.15 Wm^{–}^{1}K^{–}^{1})

**Quick Answers:**

1) 2520 J/s

2) 138.96 kJ

3) 24 J/s

**Worked Answers:**