Which of the following is not an example of work?
a. raising a barbell over your head
b. picking up a box off the floor
c. holding a tray in the cafeteria line
d. pushing a box across the floor

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