What is Energy?
Energy is the ability or capacity to do work
- Work is the process of moving an object
Energy is the ability or capacity to move an object
Energy Transformations
Energy can be transformed from one type to another
You can transfer energy from one object to another by doing work
Work-Energy Theorem
- Work done on a system by an external force changes the energy of the system
Kinetic Energy
Kinetic Energy is energy of motion
- The ability or capacity of a moving object to move another object
Potential Energy
Potential Energy (U) is energy an object possesses due to its position or state of being
Gravitational Potential Energy (Ug) is the energy an object possesses because of its position in a gravitational field
Elastic Potential Energy (Us)
Chemical Potential Energy
Electric Potential Energy
Nuclear Potential Energy
A single object can have only kinetic energy, as potential energy requires an interaction between objects
Internal Energy
The internal energy of a system include the kinetic energy of the objects that make up the system and the potential energy of the configuration of the objects that make up the system
Changes in a system's structure can result in changes in internal energy
Gravitational Potential Energy (Ug)
Conservative Forces
A force in which the work done on an object is independent of the path taken is known as conservative force
A force in which the work done moving along a closed path is zero
A force in which the work done is directly related to a negative change in potential energy (W=-ΔU)
Conservative Forces | Non-Conservative Forces |
---|---|
Gravity Elastic Forces Coulombic Forces |
Friction Drag Air Resistance |
Newton's Law of Universal Gravitation
The gravitational force of attraction between any two objects with mass
Force from Potential Energy
Summary