Hot water flows through two pipes. Each pipe is covered by an insulating sleeve, P or S. The sleeves cover the same area of pipe, and the temperature difference across each sleeve is the same.
| Sleeve | Thickness in mm\mathrm{mm}mm | Thermal conductivity in W/m K\mathrm{W/m\ K}W/m K | Measured rate of energy transfer in W\mathrm{W}W |
|---|---|---|---|
| P | 10 | 0.04 | 24 |
| S | 30 | 0.20 | 40 |
Compare the rate of energy transfer through sleeves P and S, and explain the difference.