Post on 22-Dec-2015
Enduring Understandings• Energy appears in different forms such as mechanical
energy, gravitational energy, heat energy, and electric and magnetic energy.
• Energy cannot be created or destroyed, but only changed from one form into another.
• Transformations of energy usually release some energy typically in the form of heat.
• Temperature changes as heat is transferred from a hotter object to a colder one.
• Heat transfer occurs by conduction, convection, or radiation.
• Series and parallel circuits can be used to control the amount of electrical energy produced.
• Every object exerts gravitational force on every other object. The force depends on the mass of the objects and the distance between them.
Explain energy transformation in terms of the Law of Conservation of
Energy• The Law of Conservation of Energy states that
energy cannot be created or destroyed but can only be changed form one form into another.– Example: Your car changes chemical energy (gas)
into mechanical energy (energy of motion), heat energy (thermal), and sound energy) . No energy is created or destroyed.
– Some may be converted into unwanted forms (heat).
Explain the relationship between potential and kinetic energy
• Potential energy is the stored energy that an object has due to its shape, position (height) or chemical composition.– Examples:
• Gravatitional Potential Energy
• Elastic Potential Energy
• Chemical Potenital Energy
• Kinetic energy is energy of motion– Depends on mass and speed. An increase in
speed causes a greater increase in kinetic energy than increase in mass.
– Potential energy is converted into kinetic energy when an object is acted on by a force and is set in motion. As the object slows the kinetic energy is converted back to potential energy. No energy is created or destroyed.
Compare and contrast the different forms of energy (heat, light,
electricity, mechanical motion, sound) and their characteristics.
• Thermal Energy (Heat Energy)– The total amount of energy from the movement
of particles in matter.
• Light Energy (Electromagnetic)– Energy that comes from electromagnetic energy such
as visible light.– Can travel through empty space– Includes visible light, ultraviolet light, x rays, and
microwaves.
• Mechanical Motion– Involves the position and motion of objects.– Mechanical energy is the combination of potential
energy and kinetic energy. ME=PE + KE
• Sound Energy– Energy that is the transfer of vibrations through a
solid, liquid, or gas.– Sound cannot travel through space.
Describe how heat can be transferred through matter by the collisions of
atoms (conduction) or through space (radiation) or through a liquid or gas
(convection)
• Conduction – transfer through physical contact.• Convection – transfers energy through a liquid or
gas.• Radiation – transfers energy through EM waves.