A pair of speakers on two sides of a stage are playing identical pure tones. When you stand in the center, equally distant from the two speakers, you hear the sound loud and clear. Why does the intensity of the sound diminish considerable when you step off to one side?

An inclined plane wrapped around a metal shaft is a a. lever b. screw c. pulley d. wedge

Which are advantages of renewable resources? check all that apply. renewable energy supplies are completely reliable everywhere. some renewable resources will never be used up. little or no waste is produced by renewable resource plants. electricity can be generated in large quantities. many renewable energy facilities have lower operating costs.

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.