Air enters a compressor operating at steady state at 15.4 lbf/in.2 , 80◦f with a volumetric flow rate of 424 ft3 /min and exits at 176.4 lbf/in.2 , 260◦f. heat transfer occurs at a rate of 6800 btu/h from the compressor to its surroundings. assuming the ideal gas model for air and neglecting kinetic and potential energy effects, determine the power input, in hp.

Researchers conducted an experiment to identify the effects of three different hand sanitizers on the growth of bacteria. the researchers grew one type of bacteria in twenty-four identical covered petri dishes. then, they opened eighteen petri dishes and applied the three hand sanitizers to six petri dishes each. they left the remaining six petri dishes closed as a control group. when the researchers measured the growth of bacteria two days later, the six dishes that had no hand sanitizer showed the least amount of bacterial growth. the researchers concluded that not using any hand sanitizer would lead to the least bacterial growth. which statement best explains why the researchers’ conclusion was not justified? the experiment tested too many variables. the control group was not treated the same as the experimental group. the sample size of twenty-four petri dishes is not large enough. the single type of bacteria is not adequate to make any conclusions.