Unit A - Properties of Energy

SOI: Scientific and Technical Innovations can transform and change energy, resulting in positive or negative impacts for people and the environment.

Unit A: Energy Transformations

​(Global Context)

(Key Concept)

​Matter Vs Energy

​	​MATTER	​ENERGY
​Definition	​Anything that has mass and volume because it is made of atoms.	​The ability to do work or apply a force. Energy has no mass or volume.
Examples​	​You, air, computer, water, buildings	​Light, thermal energy from warm objects, kinetic energy from moving
​Measurement	​Use a scale	​Calculate from measuring speed, mass, height, etc.
​Units	​grams (g), kilograms (kg)	​Joules (J)

Open Ended

What is something made of matter that we haven't already said? Hint: If it has mass, it is matter! So think of anything you could take the mass of...

​Systems

​Use the image on the right to complete the diagram in your workbook.


For example:

You try... Complete the table in your workbook classifying the different examples.

​System	​Catapult	​Earth	​Closed Bottle	​Lake	​Person	​Universe
​Exchange Matter?	Yes	No*	​No	​Yes	​Yes	​No
​Exchange Energy?	Yes	Yes	Yes​	Yes​	Yes​	No​
​Type of System?	Open	Closed*	Closed​	Open​	Open​	Isolated

​Check your answers...

* It can be argued Earth is an open system due to some matter exchange (meteorites and some gas escaping from our atmosphere into space). However, we generally say it is approximately closed since that matter exchange is negligible.

Complete the chart in your workbook using the textbook.

​Let's discover the types & forms of energy!

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Energy can transfer and transform.

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Open Ended

What example of energy transfer (outside) did you write down?

Open Ended

What example of energy transformation (outside) did you write?

Don't get pre-occupied with winning. If you get a question wrong, ensure you understand why the right answer is correct. Ask your teacher to come over and explain if you need.

Master this Blooket on energy transfers & transformations.

​https://dashboard.blooket.com/set/64ceeaf5a88a121ebbf0f63b

​Calculating Gravitational Potential Energy (GPE)

​Gravitational Potential Energy = mass x acceleration due to gravity x height change
E_g = mgΔh
mass units: kg
g units: m/s² or N/kg (on Earth = 9.8 m/s²)
h units: meters (m)
E_g units: Joules (J) or kg m²/s²

​E_g = mgΔh

Conceptually… this tells us that:

• Potential energy is proportional to the m, g and h.

• If we double the height above the surface, E_g doubles.

• If we triple the mass of the object, E_g triples.

• If we took the mass to a planet with half the g of Earth, then the E_g would halve.

• If we doubled both the mass and the height, then E_g would quadruple (2 x 2 = 4)

In your workbook, choose an object, choose a height and measure its mass. Then calculate its E_g!

Ask your teacher to check you did it correctly, then try the practice questions!

You Try...

​Calculating Mechanical Kinetic Energy (KE)

​Mechanical Kinetic Energy = 1/2 x mass x velocity squared
E_k = 1/2mv²
mass units: kg
velocity (v) units: m/s
E_k units: Joules (J) or kg m²/s²

​E_k = 1/2mv²

Conceptually… this tells us that:

• Kinetic energy (E_k) is proportional to the mass.

• This means that if we double m, then E_k would be doubled.

• E_k is proportional to the square of the velocity.

• This means that if velocity is doubled, the E_k is quadrupled (2² = 4)

• If we tripled the velocity, then E_k becomes 9 times larger (3² = 9)

Ask your teacher to check your answer, then start the practice problems.

​Law of Conservation of Energy

​Energy cannot be created nor destroyed, it only changes (transforms) from one form to another. In other words, energy in = energy out.

​For example, when you kick a soccer ball up in the air:

- mechanical kinetic energy is converted to gravitational potential energy

- the conservation of energy tells us how high the ball can go depends on how much energy you put into it originally.

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Drag and Drop

As objects go upwards, their ​

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is converted to ​

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.

Drag these tiles and drop them in the correct blank above

mechanical kinetic energy

gravitational potential energy

Drag and Drop

At the the highest point, the object temporarily ​

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and only has ​

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.

Drag these tiles and drop them in the correct blank above

stops

gravitational potential energy

mechanical kinetic energy

Drag and Drop

When the height is zero, the object is moving ​

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and only has ​

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.

Drag these tiles and drop them in the correct blank above

fastest

mechanical kinetic energy

gravitational potential energy

Draw

Using what you know about conservation of energy, fill in the blanks.

Open Ended

What type of energy and amount of energy should fill in the box?

In your workbook the comprehension questions.

You Try...

​Checking Answers...

​SUMMARY

​In partners discuss the answers to these & in 5 min or we'll randomly select to share!