PHYS1171 Lecture Notes - Lecture 5: Electric Potential Energy, Gravitational Energy, Mechanical Energy
Document Summary
Important to carefully consider all sources of energy: e. g. lifting an object raises its potential energy- at an energy cost to the lifter. Using kinematics, we are able to determine the height reached by an object with an initial upwards velocity: Quiz: the total energy of a closed system is 42,000 j. At some later stage the total energy will have decreased. False: frictional effects decrease the mechanical energy of a system. False: efficiency is a measure of how much energy is consumed by a system. The zeroth law of thermodynamics: define the concept of a temperature scale. If two systems are each in thermal equilibrium with a third, they are also in thermal equilibrium with each other. E. g. a human body will do work on the pedals of a bike when riding up a hill (work is done by the body) in turn lowering the internal energy of the body.
