Energy Bundle Lessons

PS 3-Energy

Kinetic energy is the energy stored in an object.

​Potential Energy

Kinetic energy is the energy in motion.

​Kinetic Energy

Energy

• This type of potential energy is the energy of an object that is stretched or compressed.

  • Examples of this would be a bow, slinky, or spring

​Elastic Potential Energy

• This type of potential energy depends on the height of the object from Earth's surface.

  • This means if something is sitting on the ground the height is 0 m.

​Gravitational Potential Energy

Types of Potential Energy

GPE=ham

This is used for objects that are stationary.

h= height meeasured in meters

a= acceleration due to gravity sometimes written as g (9.8m/s² )

m= mass measured in grams

Potential Energy

KE= 0.5mv²

This is used for objects that are moving.

m= mass measured in grams

v= velocity measured in m/s

​Kinetic Energy

Formulas needed

Kinetic/Potential Energy Info

• The final energy of a system is equal to the intial.

• The gravitational Potential Energy of an object is converted to the kinetic energy of motion as the object falls.

• This means when an object sits on a counter and has 5 J of energy (Potential) then is pushed off the side (Kinetic because it is falling) the Kinetic energy will be 5J as well.

Remember that energy cannot be created or destroyed it only changes from one form or another.

Forms of Energy

• Mechanical Energy- is the sum of an object's potential and kinetic energy.

  • (KE + PE)_beginning= (KE + PE)_end.

    • This is not limited to machines this can be athletes or a bouncing ball.

• Thermal Energy- is the sum of the object's subatomic particles potential and kinetic energy.

  • This has to do with the movement of heat.

  • As themeral energy increases an object will get warmer, some get so warm that they emit light.

Forms of Energy

• Chemical Energy- is the energy stored in chemical bonds.

  • This energy is released when those bonds are broken.

    • Examples would be the breakdown of ATP from food or the burning of wood or fuels.

• Electrical Energy- this is associated with electrical charges and devices.

  • Examples of this are batteries that convert chemical energy into electrical energy.

    • It does also occur in nature in the form of lightning.

Forms of Energy

• Electromagnetic Energy- is the form of energy that comes through space in the form of waves such as Uv rays, visible light and X-rays.

  • These types of rays are often used for communication due to the ability to travel long distances.

• Nuclear Energy- is the energy stored in atomic nuclei. This can be used to create electricity with the help of a nuclear fission or fusion reactions.

  • Fission releases energy by splitting nuclei

  • Fussion releases energy when a less massive nuclei is combine to form a massive nucleus.

Remember that energy can move between all of the forms listed previously as well as be released as sound. All energy must be conserved in a question even if it changes form. 

Multiple Choice

When you heat a pot of water over a flame, what form of energy is added to the water?

• Kinetic Energy

• Elastic Potential Energy

• Chemical Energy

• Mechanical Energy

• Thermal Energy

Multiple Choice

What kind of energy is represented by an archer stretching a bow string?

• Kinetic Energy

• Elastic Potential Energy

• Chemical Energy

• Mechanical Energy

• Thermal Energy

Multiple Choice

The energy of a moving object is

• kinetic energy

• potential energy

• chemical energy

• nuclear energy

Multiple Choice

If the speed of an object doubles, its kinetic energy

(think about the formula maybe use some numbers)

• doubles.

• quadruples.

• stays the same.

• is halved.

Multiple Choice

An example of an object having elastic potential energy is

• a stretched spring.

• books on a shelf.

• a moving arrow.

• a falling oyster.

Multiple Choice

An example of electromagnetic energy is

• a falling rock.

• a stretched spring.

• a speeding train.

• sunlight.

Multiple Choice

Energy stored in the bonds between atoms is called

• kinetic energy.

• mechanical energy.

• chemical energy.

• thermal energy.

Multiple Choice

Mechanical energy is

• found in machinery only.

• usually measured at the atomic level.

• the sum of the chemical and thermal energy of an object.

• the sum of the kinetic and potential energy of an object.

Multiple Choice

An example of the conversion of gravitational potential energy into kinetic energy is

• a falling raindrop.

• a gasoline-powered enegine.

• striking a match.

• a hokey puck sliding on ice.

Multiple Choice

The law of conservation of energy states that

• energy cannot be converted from one form to another.

• energy cannot be created or destroyed.

• energy resources must be used efficiently.

• energy is constantly being lost to friction.

Thermal Energy and Heat

Thermal Energy Transfer

• Heat is the transfer of thermal energy from one object to another because of a temperature difference.

• Temperature is the average kinetic energy of the particles in an object.

• Thermal energy depends on the mass, temperature, and the phase (solid, liquid, or gas) of the object.

Heat and Thermodynamics

​Conduction

• Conduction is the tranfer of thermal energy with no transfer of matter. This occurs when objects are touching.

  • Conduction in gases is slower than in liquids and solids because the particles in a gas collide less often.

    • Themeral Conductors are materials that conduct thermal energy well. (Wire racks in ovens, pots and pans etc.)

    • Themermal Insulators are materials that conduct thermal energy poorly. (Air, wool, and plastic foam cups etc.)

• Radiation is the transfer of energy by waves moving through space.

  • All objects radiate energy.

  • As an object's temperature increases, the rate at chich it radiates energy increases.

​Radiation

• Convection is the transfer of thermal energy when particles of a fluid(not to be confused with liquid) move from one places to another.

  • Convection currents occur when a fluid circultes in a loop as it alternately hets up and cools down.

    • Convection currents are important for cycles in nature (water, carbon, etc.)

​Convection

Heat and Thermodynamics Cont.

Thermodynamics

​the study of conversions between themeral energy and other forms of energy.

​First Law of Thermodynamics

• The first law of theromodynamics states tht energy is conserved.

  • If energy is added to a system, it can either increase the thermal energy of the system or do work on the system. But no matter what happens, all of the energy aded to the system can be accounted for.

​Second Law of Thermodynamics

• The second law of thermodynamics states that thermal energy can flow from colder objects to hotter objects only if work is done on the system.

  • A refigerator, for example, must do work to transfer thermal energy from the cold food compartment to the warm room air. the thermal energy is released by coils at the bottom or in the back of the refridgerator.

Third Law of Thermodynamics

• The third law of thermodynamics states that absolute zero cannot be reached.

  • Scientists have been able to cool matter almsot all of the way to absolute zero but they still haven't been able to reach it.

Multiple Choice

The best thermal insulators

• conduct heat well.

• are gases.

• are metals.

• have free electrons.

Multiple Choice

A blow dryer transfers thermal energy mainly by

• conduction.

• convection.

• radiation.

• specific heat.

Multiple Choice

Which statement is NOT true about radiation?

• All objects radiate.

• Hot objects radiate faster thann cold objects.

• Radiation only transfers energy in matter.

• The sun's energy reaches Earth by radiation.

Multiple Choice

Energy added to a system

• does work or increases thermal energy.

• cannot heat the environment.

• is converted to radiation.

• reduces the kinetic energy of the system.