What is energy? The ability to cause change.
THERMAL internal motion of particles The ability to cause change. NUCLEAR changes in the nucleus ENERGY MECHANICAL motion of objects CHEMICAL bonding of atoms joules (J) ELECTRICAL motion of electric charges
EnErgy is nature s way of keeping score. We sense energy only when the score changes, either a transformation from one form of energy to another, or a transfer of energy from one point to another.
The Law of Conservation of Energy Energy cannot be created or destroyed; it may be transformed from one form into another, but the total amount of energy never changes.
How is energy classified? All Energy Potential Energy Kinetic Energy Gravitation Potential Energy Elastic Potential Energy Chemical Potential Energy
What is Potential Energy? o Energy that is stored and waiting to be used later
What is Gravitational Potential Don t look down, Rover! Good boy! Energy? o Potential energy due to an object s position o P.E. = mass x height x gravity
m = mass (kg) h = height (m) g = accel due to gravity (9.8 m/s 2 ) PE = mgh
Potential Energy (PE) stored energy depends on position or configuration of an object Which boulder has greater gravitational PE?
What is Elastic Potential Energy? o Potential energy due compression or expansion of an elastic object. Notice the ball compressing and expanding
What is Chemical Potential Energy? o Potential energy stored within the chemical bonds of an object
What is Kinetic Energy? o Energy an object has due to its motion o K.E. =.5(mass x speed 2 )
Kinetic Energy Kinetic Energy (KE) energy in the form of motion depends on mass and speed Which has the most KE? 80 km/h truck Which has the least KE? 50 km/h motorcycle 80 km/h 50 km/h 80 km/h
Potential energy of position or energy in storage. Water behind a dam Hammer over head Food on the plate Kinetic energy of motion, the form capable of doing work Flowing water A falling hammer Electrons regenerating ATP in a cell
Forms of energy and energy transformations
Forms of energy 1. Mechanical energy 2. Thermal (heat) energy 3. Electromagnetic energy 4. Electrical energy 5. Nuclear energy 6. Chemical energy
What is the source of our energy? The source of practically all our energy is the Sun.
What is Mechanical Energy? o Energy due to a object s motion The bowling ball has mechanical energy. When the ball strikes the pins, mechanical energy is transferred to the pins!
Examples of Mechanical Energy
What is Electrical Energy? o Energy caused by the movement of electrons o Easily transported through power lines and converted into other forms of energy
What is Electromagnetic Energy? o Light energy o Includes energy from gamma rays, xrays, ultraviolet rays, visible light, infrared rays, microwave and radio bands
What is Electromagnetic Energy?
What is Chemical Energy? o Energy that is available for release from chemical reactions. The chemical bonds in a matchstick store energy that is transformed into thermal energy when the match is struck.
Examples of Chemical Energy
What is Thermal Energy? o Heat energy o The heat energy of an object determines how active its atoms are. A hot object is one whose atoms and molecules are excited and show rapid movement. A cooler object's molecules and atoms will show less movement.
QUIZ TIME! Electrical energy is transported to your house through power lines. When you plug an electric fan to a power outlet, electrical energy is transform into what type of energy? MECHANICAL ENERGY
MECHANICAL ENERGY QUIZ TIME! What type of energy cooks food in a microwave oven? ELECTROMAGNETIC ENERGY What type of energy is the spinning plate inside of a microwave oven?
QUIZ TIME! What energy transformation occurs when an electric lamp is turned on? ELECTRICAL ENERGY ELECTROMAGNETIC ENERGY
What types of energy are shown below? Mechanical and Thermal Energy (Don t forget friction)
What types of energy are shown below? Electrical, Mechanical and Electromagnetic Energy
What type of energy is shown below? Chemical Energy
What type of energy is shown below? Chemical Energy (yummy)
What type of energy is shown below? Thermal Energy
What types of energy are shown below? Mechanical, Electromagnetic, Electrical, Chemical and Thermal Energy