1. Energy & Energy Transformations W. J. Lester Earth Science Team Iver C. Ranum High School March 2007

2. 1 - Thermal Energy or Heat is the internal energy in substances is the vibration and movement of the atoms and molecules within substances. geothermal energy is an example of thermal energy.

3. 2 - Radiant Energy is electromagnetic energy that travels in transverse waves. Radiant energy includes visible light, x- rays, gamma rays and radio waves. Light is one type of radiant energy. Solar energy is an example of radiant energy.

4. Types of Waves Mechanical waves require a material medium to travel (air, water, ropes). These waves are divided into three different types. –Transverse waves cause the medium to move perpendicular to the direction of the wave. –Longitudinal waves cause the medium to move parallel to the direction of the wave. –Surface waves are both transverse waves and longitudinal waves mixed in one medium. Electromagnetic waves do not require a medium to travel (light, radio). Matter waves are produced by electrons and particles.

5. Transverse Wave

6. Longitudinal Wave

7. Waves

11. Frequency The number of vibrations per second is called frequency and is measured in hertz (Hz). Here's the equation for frequency: f = 1 / T

12. Wave Velocity By knowing the frequency of a wave and its wavelength, we can find its velocity. Here is the equation for the velocity of a wave:

13. Wave Problem A radio wave has a frequency of 93.9 MHz (93.9 x 10 6 Hz). What is its period? f = 93.9 x 10 6 Hz f = 1 / T T = 1 / f T = 1 / 93.9 x 10 6 Hz T = 1.06 x 10 -8 s

14. 3 - Electrical Energy ….is the movement of electrical charges. Everything is made of tiny particles called atoms. Atoms are made of even smaller particles called electrons, protons, and neutrons. Applying a force can make some of the electrons move. Electrical charges moving through a wire is called electricity. Lightning is another example of electrical energy.

15. 4 - Mechanical Energy - Kinetic Energy ….is motion––of waves, electrons, atoms, molecules, substances, and objects. Kinetic Energy is Mechanical Energy. KE = 1/2mv 2 –m ≡ mass –v ≡ velocity

16. 4 – Mechanical Energy - Potential Energy …..is stored energy and the energy of position. PE is a type of Mechanical Energy. PE = mgh –m ≡ mass (kg) –g ≡ acceleration due to gravity constant; -9.8 ms -1 –h ≡ height (m)

17. Classify the following as examples of potential energy or kinetic energy: a bird sitting in a tree a bird flying through the air a book falling off a disk roller coaster a chicken on a barn roof a burrito on a plate that is on a table

18. 5 - Chemical Energy ….is energy stored in the bonds of atoms and molecules. It is the energy that holds these particles together. Biomass, petroleum, natural gas, and propane are examples of stored chemical energy.

19. 6 - Nuclear Energy ….is energy stored in the nucleus of an atom–– the energy that holds the nucleus together. The energy can be released when the nuclei are combined or split apart. –Nuclear power plants split the nuclei of uranium atoms in a process called fission. The sun combines the nuclei of hydrogen atoms in a process called fusion. –Scientists are working on creating fusion energy on earth, so that someday there might be fusion power plants.

20. Conservation of Energy To scientists, conservation of energy is not saving energy. The law of conservation of energy says that energy is neither created nor destroyed. When we use energy, it doesn’t disappear. We change it from one form of energy into another.

21. Kinetic Energy and Potential Energy Transformation

23. Energy Cycle in Living Things