Work, Energy and Power Flashcards
Mechanical energy
The sum of gravitational potential and kinetic energy of a body at a point.
Gravitational potential energy
The energy an object possesses due to its position relative to a reference point.
Kinetic energy
The energy an object has as a result of the object’s motion.
Law of Conservation of Energy
The total energy in a system cannot be created nor destroyed; only transferred from one form to another.
Properties of Non-conservative forces (forces that change the total mechanical energy)
Change the mechanical energy of an object
The work they do depends on the path taken by the object.
Properties of Conservative forces (forces that do not change Emech)
Do not change the mechanical energy of an object.
The work they do is independent ofthe path taken by the object.
Principle of conservation of mechanical energy
In the absence of air resistance or any external forces, the mechanical energy of an object is constant.
Work done (on an object by a force)
The product of the displacement and the component of the force parallel to the displacement
The work-energy theorem
the work done by a net force on an object is equal to the change in the kinetic energy of the object.
Power
The rate at which work is done or the rate at which energy is transferred.
One watt
The power when one joule of work is done in one second.
Efficiency
The ratio of output power to input power
