1. An Antarctic explorer builds a temporary shelter from wind-pack snow. The shelter is roughly hemispherical with an inside radius of 1.5 meters. After completing the shelter,the explorer crawls inside and closes off the entrance with a block of snow. Assume the shelter is now air tight and loses negligible heat by conduction through the walls. If the air temperature when the explorer completes the shelter is -10°C, how long will it take before the air temperature inside reaches 10°C? Assume the explorer does not freeze to death or suffocate, but sits patiently waiting for the temperature to rise. The explorer generates body heat at a rate of 300 kJ/h. (10 pts)

Fig: 1