Aradio telescope is used to study radio waves that come from stars and galaxies. what type of wave is a radio wave?

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 final velocity of the initial velocity of 25 and -50?

When you push downward on a book at rest on a table, you feel an upward force. does this force depend on friction? defend your answer.