What happens to thepressure on a gas if the area of the applied pressure is decreased to 1/3 the original area

Question

-what happens to the kinetic energy if the mass is quadrupled (velocity stays the same)?
-what happens to the kinetic energy if the velocity is decreased to 1/5 the original velocity?

Answer 1

a.) It results in a decrease in pressure, or a pressure loss within the gas stream.

b.) It results in a pressure increase in the gas stream ..commonly referred to as static pressure regain.

These pressure losses and rises are dealt with with in every hot air or air conditioning duct system design.