Examine the Doppler effect illustration above. Assume the red dot is a police car with it's siren on. Which direction is the police car traveling?
A)
down
B)
left
C)
right
D)
up

The freezing and boiling point of a substance changes as the air pressure around it changes. for example, at a lower air pressure (higher altitude) it is easier for water molecules to escape from liquid into the air. in a high altitude city such as denver, colorado compared to a sea-level city such as houston, texas, water