4 Potential and Kinetic Energy Potential energy is energy that is stored in an object.Kinetic energy is energy of motion.
5 Potential energyPotential energy (P.E.) is the ability of an object to do work because of its position. work done by the object = P.E. lostwork done on the object = P.E. gained.
6 Potential energyPotential energy is a type of energy that is "hidden" in some way. It is a type of energy that can be converted to other forms and often is related to some attractive or pushing forces.
10 Gravitational Potential Energy There is a constant attractive force between the Earth and everything surrounding it, due to gravity.To lift something off the ground it takes energy, so just by lifting an object, that object now has higher gravitational potential energy.
11 Gravitational potential energy is typically converted into kinetic energy (an object falling) before it is converted into any other type of energy.Hydroelectric power is generated this way. As the water falls, it turns a turbine, which pushes electrons around, creating an
16 Chemical Potential Energy A chemical bond can be thought of as an attractive force between atoms.Because of this, atoms and molecules can have chemical potential energy.Anytime two atoms form a strong covalent or ionic bond or two molecules form a chemical energy is converted into other forms of energy, usually in the form of heat and light.
17 Strong bonds have low chemical energy and weak bonds have high chemical energy.
20 Kinetic energy is the energy of motion. Any object that is moving has kinetic energy.Ball Moving HorizontallyKinetic Energy Equationm = mass (in kg), v = velocity (in m/s), and KE = kinetic energy (in J = joules).
21 Remember, the units for energy are Joules - Kilogram . meters / sec2
22 Practice Problems:1. A 12 pound bowling ball is held 20 feet above the floor. Calculate its GPE.2. A 2kg object is traveling at 4m/s. Calculate its KE.
24 Law of Conservation of Matter and Energy: the total matter and energy in the universe is always conserved.
25 Can energy be changed into matter? Think of matter and energy as two forms of the same thing that can be converted from one to another.
26 E=mc2While it is possible to change matter into energy and energy into matter, the sum of the two is always constant.Einstein's equation shows this relationship.E = Energy (Joules)m = mass (kg)c = speed of light (300,000 km/s)
27 The two most common energy conversions are: Potential energy changing into kinetic energy.Kinetic energy changing into potential energy
28 Mechanical energy= potential energy + kinetic energy Mechanical is energy due to the motion of an object
33 Mechanical energy There are two main types of mechanical energy. Motion energy: This is the energy something has because it is movingStored mechanical energy: This is energy something has stored in it because of its height above the ground or because it is stretched or bent or squeezed
34 Electrical energyThe energy that flows through wires and powers the lights and appliances in your home.The energy is in the form of moving electrons
35 Electromagnetic energy Visible light or radiant energyX raysRadio wavesMicrowavesThis form of energy can travel through a vacuum
36 Concept Understanding: 1. Assume that all the matter in your body could be converted into energy, how many Joules of energy would that be?Hint: 1 pound = 0.5 kgShow all your work used to solve this problem.2. Give one example of each of the following energy conversions:Chemical energy changing into heat energy.Heat energy changing into mechanical energy.Nuclear energy changing into heat energy.Mechanical energy changing into electromagnetic energy.
37 Conservation Matter can be changed into energy Energy can be changed into matterNeither can be created or destroyed