Mechanical waves are created when a source of energy causes a medium to ?

Determine el momento angular de un rueda de 3000g moviendose a 10m/s con un radio de giro de 400cm

Ihave a density of 1.61g/cm^3 and a mass of 28g. find the missing value

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.