Energy Transformations and Conservation

Review

• What are the 2 types of energy?• What are the 6 forms of energy? 1 Form + 5

other forms. Why?

Overview

• Energy can be transformed from one form of energy into other forms.

• Conservation of energy/First Law of Thermodynamics.

• Energy and Matter.• Source of all Energy.

Single Transformation

• Sometimes in order to do work one form of energy must be transformed into another.

• Ex. A toaster transforms electric energy into thermal energy.

• Ex. A cell phone transforms electric energy into electromagnetic energy to make a call.

• Ex. Your body transforms chemical energy in food into mechanical energy to move your muscles.

Multiple transformations

• Often times a series of energy transformations is needed to do work.

• Ex. Striking a match• ME Thermal Releases Chemical Thermal

+ Electromagnetic.• Car• Electrical Thermal Releases chemical

Thermal ME + Electrical

Kinetic and Potential Transformations

• Energy is constantly changing from Kinetic to Potential and back to Kinetic.

• Ex. Ball bouncing• Ex. Pendulum swinging

Conservation of Energy

• Energy cannot be created or destroyed.• The energy is just transformed into other

forms. • Ex. Spinning ball/spinning top.• Why does the ball or top stop spinning?• Friction is the source of a lot of lost energy. It

is not destroyed just converted into heat.

Energy and Matter

• What is conservation of Matter/Mass?• Mass cannot be created or destroyed and

neither can energy.• Albert Einstein’s theory of relativity– E=mc2

• E = energy• M= mass• C = speed of light (constant does not change)

Energy and Matter

• What does it mean?• A small amount of mass can be converted into

a large amount of energy.• This is how nuclear energy works.