Work, Energy, Power Flashcards
Work done on an object by a force?
The product of the displacement and the component of the force parallel to the displacement. The word parallel is important because no work is done if the applied force is perpendicular to the displacement. Work can be described as done by a force, against a force or on an object.
Wasted Work?
The work done against friction, it therefore cannot be used to accelerate an object.
Useful Work?
The work done by the net force to accelerate the object and give it Kinetic Energy.
Gravitational Potential Energy?
The energy an object possesses due to its position/height relative to a reference point.
Kinetic Energy?
The energy an object has as a result of its motion.
Mechanical Energy?
The sum of gravitational potential energy and kinetic energy at a point.
Law of Conservation of Energy.
The total energy in a system cannot be created nor destroyed, only transformed from one form to another.
Principle of Conservation of Mechanical Energy.
In the absence of air resistance or any external forces, the mechanical energy of an object is constant. Statement necessary before calculation: Mechanical energy is conserved in an isolated system.
Conservative Force?
When the work done is independent of the path taken. Ex: Gravitational Force, Electrostatic Force and the elastic force in a spring.
Non-conservative Force?
When the work done in moving an object between two points depends on the path taken. Ex: Friction, tension, air resistance.
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.
Watt?
Defined as the unit of power when one joule of work is done in one second. What does the equation look like?
Efficiency?
The ratio of output power to input power. Add, “in a circuit” when circuits are involved.
Energy?
The ability to do work.
