Unit 7: Energy Transformations

Unit 7: Energy Transformations

I know...

• how to identify the type of energy when presented with an image.

Learning Target

I can...

• ​construct explanations for energy transformations within a system.

​​Success Criteria

Whenever work is done, energy is transformed or transferred to another system.

• Energy is the ability to do work.​

Energy and Work

Energy and Work

Misconception:

• only things that are moving have energy.

  • Energy can be present in an object or a system when no​thing is happening.

  • Once an object moves in the direction of the force being applied, we can observe work being done as energy is transferred ​from one object to another

Types of Energy

​Mechanical	​Potential	Kinetic
Chemical	Thermal	Nuclear
Electrical	​Electromagnetic	Sound

​Each of these forms of energy can be converted into other forms of energy.

definition: the energy associated with the motion or position of an object.

• this is the sum (total amount) of potential and kinetic energy in a system.

  • Kinetic energy: the energy of motion

  • Potential Energy: the energy that is stored in an object (energy of position)

Mechanical Energy

definition: energy that results from the flow of electrons

• electric charges can exert forces that do work​

Electrical Energy

definition: the energy stored in chemical bonds

• when bonds are broken the released energy can do work​

Chemical Energy

definition: energy given off as heat (friction)

• Force vs Friction

  • Friction is a type of force that opposes motion, or makes it difficult for an object to move across a surface.​

​

Thermal Energy

definition: the energy stored in atomic nuclei

• Remember:

  • nuclear fission releases energy by splitting nuclei apart

  • nuclear fusion combines 2 nuclei into a larger nucleus​ which releases energy

Nuclear Energy

definition: energy that moves through a substance such as air or water

• this is caused by vibrations (periodic back-and-forth motion).

• Solids, liquids and gases can transmit sounds as waves.

​

Sound Energy

definition: energy that travels through space in the form of waves (also called radiant energy)

• visible light and x-rays are examples of electromagnetic energy​

Electromagnetic Energy

This is the process of changing energy from one form to another

Energy Conversions

​Chemical

Energy​

​Mechanical

Energy​

​Kinetic

Energy​

States that energy cannot be created nor destroyed, it can only be changed (transferred).

• energy can be transferred to another object/system or into another form

  • example:

    • a roller coaster

      • at the top of the coaster you have potential energy but when you drop it turns to kinetic energy

Law of Conservation of Energy

Energy Transformation Practice

What type of energy transfer is being shown?

What type of energy transfer is being shown?

​Chemical

​Mechanical (movement)

Multiple Choice

What type of energy transformation is being shown in the image?

(eaten apple --> person riding a bike)

• chemical to light

• electrical to light

• chemical to mechanical

• light to heat (thermal)

Multiple Choice

What type of energy transformation is being shown in the image?

(battery --> flashlight)

• chemical to light

• potential to light

• chemical to mechanical

• light to heat (thermal)

Multiple Choice

What type of energy transformation is being shown in the image?

(sun --> tree)

• chemical to light

• electrical to light

• radiant to chemical

• light to heat (thermal)

Multiple Choice

What type of energy transformation is being shown in the image?

(plug --> lamp)

• chemical to light

• electrical to light

• radiant to chemical

• light to heat (thermal)