7. A stereo is able to convert 20% of its electrical energy into sound. If 1000 J of sound energy is produced, calculate the electrical energy used [Show all work].

8. A vehicle is only 18% efficient. How was the other 82% of the energy lost?

Jet streams are relatively narrow bands of strong wind in the upper levels of the atmosphere. the winds blow from west to east in jet streams but the flow often shifts to the north and south. jet streams follow the boundaries between hot and cold air. the earth's rotation is responsible for the jet stream as well.