A copper pipe with an outer radius of 0.015 m runs from an outdoor wall faucet into the interior of a house. The temperature of the faucet is 3.6° C and the temperature of the pipe, at 3.1 m from the faucet, is 28° C. In sixteen minutes, the pipe conducts a total of 253 J of heat to the outdoor faucet from the house interior. Find the inner radius of the pipe. Ignore any water inside the pipe.