A concrete driveway is 4.2 m wide. Within the concrete slab are 1 standard type K copper tubes through which heated water is pumped to keep the concrete warm during winter months. Snow that falls or...

A concrete driveway is 4.2 m wide. Within the concrete slab are 1 standard type K copper tubes through which heated water is pumped to keep the concrete warm during winter months. Snow that falls or ice that forms on the concrete will melt and fl ow off the surface. Th e copper tubes are 6 cm apart (center to center), and the line of centers of the tubes is 4 cm below the slab surface, as shown in Figure P3.18. Water within the tubes heats each tube surface to 85°C. Th e concrete surface should be at least 0°C. Th e ground beneath the slab is also at 0°C. Determine the heat-fl ow rate from one tube at this location.