Humans can hear frequencies as low as 21 hz. if sound is measured during 3 seconds how many wavelengths pass?

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

How are the crust and the inner core alike? a) they are both solid. b) they both have the same temperature. c) they are both under the same pressure. d) they are both very close to the center of the earth.

Which compound is held together by the electrostatic force between two ions? a. co2 b. cci4 c. h2s d. mgf2