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Alarge box of mass m is pulled across a horizontal frictionless surface by a horizontal rope with tension t. a small box of mass m sits on top of the large box. the coefficients of static and

Air is contained in a variable-load piston-cylinder device equipped with a paddle wheel. initially, air is at 400 kpa and 17°c. the paddle wheel is now turned by an external electric motor until 75 kj/kg of work has been transferred to air. during this process, heat is transferred to maintain a constant air temperature while allowing the gas volume to triple. calculate the required amount of heat transfer in kj/kg.

Where do magnetic lines of force enter earth?