A sound wave passes through an area of 5.5 m Square with an intensity of 7.2 x 10 exp-5 W/m square. What is the power of this sound ? 1- P = 396 x 10 exp -8 W
2- P = 3.96 x 10 exp -4 W
3- P = 39.6 x 10 exp -9 W
4- P = 0.38 x 10 exp -3 W

Aray of light traveling parallel to the principal axis of a concave mirror will be reflected through the mirror's

Ammonia enters the expansion valve of a refrigeration system at a pressure of 10 bar and a temperature of 18oc and exits at 6.0 bar. the refrigerant undergoes a throttling process. determine the temperature, in oc, and the quality of the refrigerant at the exit of the expansion valve.

What is the increase in density of a medium due to wave travel?