The siberian husky is a medium dog, weighing between 16-27kg (35-60lbs). these dogs have strong pectoral and leg muscles, allowing them to move through dense snow. if they had heavier muscles, they would sink deeper into the snow and move slower. yet, if they had lighter muscles, they would not be strong enough to pull sleds and equipment. this is an example of which type of natural selection?

Atwo-stage air compressor operates at steady state, compression 10m^3/min of air from 100 kpa and 300k to 1200 kpa. an intercooler between the two stages cools the air to 300k at a constant pressure of 350 kpa. the compression processes are isentropic. a) calculate the power required to run the compressor, in kw b) compare the result to the power required for isentropic compression from the same inlet state to the same final pressure.