1. Energy

2. Energy Energy Capacity to do work SI unit of energy joule
2 Classes of Energy
Kinetic
Potential
F:\chemistry\chemistry\energy\08_02Ene rgyConcepts_A.html

3. 5 Forms of Energy? 5. Nuclear Energy: the nucleus of an atom is split
1. Chemical:
Energy existing within the bonds that hold atoms together
Ex: fuel, coal, food
2. Mechanical:
Matter that is in any type of motion
Ex: water coming down a waterfall, wind, car, airplane, walking, playing tennis
3. Electromagnetic:
Moving electric charges which have energy to perform work.
Ex: electric motors, light, colors of the rainbow, radio waves
4. Heat:
The internal motion of atoms that are constantly in motion.
Ex: forms of matter changing from solids to liquids then gas, heat energy is observed by temperature changes.
5. Nuclear Energy:
the nucleus of an atom is split
Ex: the sun’s energy, nuclear weapons
Applying_the_Concepts_of_Energy.asf

4. Applying_the_Concepts_of_Energy. asf What_Is_Heat_. asf Heat_Transfer
Applying_the_Concepts_of_Energy.asf What_Is_Heat_.asf Heat_Transfer.asf

5. Conservation of Energy
Energy is not created it is just converted or changed to a different form
Law of conservation of Energy
Albert Einstein’s Theory of Relativity
If a system or body gives off energy it decreases in mass
If there is an absorption of energy there is an increase in mass

6. What is Gravitational Potential Energy?
Boardworks High School Science
Gravitational and Potential Energy
What is Gravitational Potential Energy?
The GPE of an object can be calculated using this equation:
GPE = mass x gravitational field strength x height
Mass is measured in kilograms (kg).
Gravitational field strength is measured in newtons per kilogram (N/kg), usually taken as 10 N/kg on Earth.
Teacher notes
An alternate version of the equation is ‘GPE = weight x height’, as ‘weight = mass x gravitational field strength’.
Gravitational field strength can also be referred to as gravity.
Height is measured in meters (m).
GPE is measured in joules (j).

7. Boardworks High School Science Gravitational and Potential Energy
Factors affecting GPE
Teacher notes
This activity could be used to introduce the factors affecting the GPE of objects, and the ‘GPE = mgh’ equation.

8. Boardworks High School Science Gravitational and Potential Energy
Calculating GPE
An eagle with a mass of 2 kg flies at a height of 200 m above the ground.
How much gravitational potential energy does the eagle have?
GPE = mass x gravitational field strength x height
Photo credit: © 2007 Jupiterimages Corporation
= 2 x 10 x 200
= 4,000 J

9. Boardworks High School Science Gravitational and Potential Energy
Calculating GPE
An apple with a mass of 200 g falls 3 m from its branch to the ground.
How much GPE will the apple have lost when it reaches the ground?
= mass x gravitational field strength x
GPE lost
change in height
Photo credit: © 2007 Jupiterimages Corporation
= x 10 x 3
= 6 J

10. Boardworks High School Science Gravitational and Potential Energy
Teacher notes
This multiple-choice activity provides an opportunity for students to practice using the ‘GPE = mgh’ equation. Students could answer each question in their books before revealing the answer on the interactive whiteboard.