How does the ozone layer affect life on earth?

Which simple machine is not part of this compound machine? a. lever b. pulley c. inclined plane d. wheel and axle

How are series and parallel circuits simililar? both have multiple paths for electrons to travel. both require resistors in their circuits. both require a switch to complete the circuit. both have at least one path for electrons to travel.

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.