A(n) is a material that causes a wave to bounce off of it.

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 a good example of instantaneous speed

When the magnetic domains in a material can be aligned, but eventually drift out of alignment, the material is