Find the frequency of a wave with a period of 0.5 seconds

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.

Matter that emits no light at any wavelength is called

The chart shows daniela’s run through her race. what is her velocity? 1.5 m/s 2 m/s 2.5 m/s 5 m/s