For a system in which to total mass does not change, energy is neither created nor destroyed. The total amount of energy in the system is conserved. Energy doesn't leave the system and energy isn't added to the system. Energy can be converted from one kind into another, but the total energy stays constant.
Example:
A ball is held at a height where it's potential energy is 500 joules. The ball is dropped and hits the ground. What is the final kinetic energy of the ball at the time it hits the ground?
The final kinetic energy at the time the ball hits the ground is 500 joules, because the final kinetic energy is equal to the potential energy. Potential energy becomes kinetic energy as the ball drops, but the total amount of energy stays constant.
Conservation of energy:
Define:
For a system in which to total mass does not change, energy is neither created nor destroyed. The total amount of energy in the system is conserved. Energy doesn't leave the system and energy isn't added to the system. Energy can be converted from one kind into another, but the total energy stays constant.Example:
A ball is held at a height where it's potential energy is 500 joules. The ball is dropped and hits the ground. What is the final kinetic energy of the ball at the time it hits the ground?The final kinetic energy at the time the ball hits the ground is 500 joules, because the final kinetic energy is equal to the potential energy. Potential energy becomes kinetic energy as the ball drops, but the total amount of energy stays constant.
Other topics
- Scalar
- Joule
- Potential
- Kinetic
Sources:http://www.grc.nasa.gov/WWW/K-12/airplane/thermo1f.html
http://www.physics247.com/physics-help/conservation-energy.shtml
http://www.physics247.com/physics-homework-help/conservation-energy.php