Describe a model that could represent the the total energy of a system as a relationship of the motion of particles on both the microscopic and macroscopic level?

The of a machine determines its "usefulness." a. input force b. output force c. mechanical advantage

Aman throws a football straight into the air. as it rises, it slows down. which type of energy is the football gaining?

Assume that a person skiing high in the mountains at an altitude of h = 15100 ft takes in the same volume of air with each breath as she does while walking at sea level. determine the ratio of the mass of oxygen inhaled for each breath at this high altitude compared to that at sea level. assume that the air composition (i.e. % of air that is oxygen) is the same at sea level as it is at 15100 ft.