which part of systems theory is the process of monitoring outputs to determine whether or not the system is working?

Shafts are machine elements that are used to a) carry axial loads b) direct shear loads c) transmit power d) rotate at constant speed e) none of the above circular and square shafts subjected to the same torque under the same circum behave a) the same way b) almost the same way

What is the heat treatment of metals? what is the benefit of it? why and how it's useful? answer in details, do not write by hand.

An electrical kettle is made out of stainless steel,weighs two pounds (when empty) with a heating element that consumes 2 kw of electricity. assuming that the water and the kettle are at the same uniform temperature at any moment of time, calculate the shortest possible time to bring 2 quarts of water from room temperature to the onset of boiling.