What is the amount of energy needed to lift something weighing one pound to a height of nine inches?

Apulley with mass mp and a radius rp is attached to the ceiling, in a gravity field of 9.81 m/s2 and rotates with no friction about its pivot.

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

Which statement is the best definition of an atom? a) anything that has mass and occupies space. b) the smallest particle that has the properties of an element. c) a substance that cannot be broken down chemically into simpler substances. eliminate d) the smallest unit of a substance that exhibits all of the properties characteristic of that substance.