Two sound sources send identical waves of 20 cm wavelength out along the +x axis. At what minimum (non-zero) separation of the sources will a listener on the axis beyond them hear: (a) the loudest sound (b) the weakest sound?

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

In a heat engine if 1000 j of heat enters the system the piston does 500 j of work, what is the final internal energy of the system if the initial energy was 2000 j? 1. write the equation 2.list out your known variables 3.plug the numbers into the equations 4.solve 5.write your solution statement that includes initial energy and final

In which type of system is power held solely by the central government and not shared with regional governments? group of answer choices federal unitary confederate oligarchic