Chapter 6 Vocab Flashcards
(26 cards)
Work
Force times distance
Net work
Change in kinetic energy of object
Positive work
When force is acted on in the same direction of motion
Negative work
When force is acted on in the opposite direction of motion
Joule
Nm, unit of work
Kinetic energy
Energy of motion
Work-energy principle
Net work= change in kinetic energy
Potential energy
Energy associated with forces that depend on position or configuration of an object relative to surroundings
Spring constant
Spring stiffness constant used to measure stiffness of a spring
Spring equation
Fs =-kx, finds out force of spring
Hooke’s law
Spring equation
Elastic potential energy
Potential energy stored as a form of deformation by an elastic object
Conservative forces
When force does not depend on the path taken but the initial and final positions (gravity)
Nonconservative forces
Work that depends on path (friction, push/pull)
Total Mechanical energy
Sum of kinetic and potential energy at any moment
Mechanical energy
Sum of kinetic and potential
Conserved quantity
Total mechanics energy of a system
Principle of conservation of mechanical energy
If only conservative forces do work, the total mechanical energy of a system neither increases nor decreases in any process. It stays constant and conserved.
Law of conservation of energy
No energy is gained/ lost in any process. It can be transformed and transferred but the total amount is constant
Dissipative forces
Energy is lost from a system when motion takes place
Power
Rate at which work is done
Horsepower
Unit of power (550ft*lb/sec)
Watt
Measure of power (J/sec)
Efficiency
Ratio of useful power output of engine to power input
