Conservation of Energy Chapter 5, Section 3 8th Grade Mrs. Boguslaw

The Law of Conservation of Energy Energy cannot be created or destroyed In a closed system, the total amount of energy is always the same All of the different forms of energy in a sustem always add up to the same total amount of energy

Friction Converts mechanical energy into thermal energy Energy is not “lost” from the system - it is changed into a different form

Noise Some mechanical energy is converted into sound energy Energy is not “lost” from the system - it is changed into a different form

If energy is always conserved, why don’t perpetual motion machines actually exist?

Thermal Energy Every time one form of energy is converted into another, some energy is converted into thermal energy Energy is not “lost” from the system - it is changed into a different form

How can we make conversions more efficient? How can we make more of the form we want to use and less “wasted” energy?

Energy Efficiency A comparison of the amount of energy before a conversion to the amount of USEFUL energy after a conversion Good way to increase efficiency = reduce friction