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Year 7 Science: Energy, Light and Sound

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Energy, Light and Sound Revision Checklist

Energy

o I can define energy and name some forms of energyo I can describe some energy transformations involved in common machines.o I know what energy efficiency means

Light

o I know that light travels quickly, in straight lines called rays from a source o I can explain why we get a reflection from a smooth surface but not a rough oneo I know what a reflected image look like compared to the original objecto I know the rule ‘Angle of incidence = Angle of reflection’o I can draw a diagram to show that Angle of incidence = Angle of reflectiono I know what the term ‘refraction’ meanso I know what happens to the direction of light rays when they speed up or slow downo I know what the terms ‘dispersion’ and ‘spectrum’ meano I know the colours of the spectrum in order

Sound

o I can explain whether sound can travel through a solid, liquid or a gaso I can explain why sound can’t travel through a vacuumo I know what causes a soundo I understand the term volume, and amplitude and its unitso I understand the term pitch, and frequency and its unitso I can draw sound waves that are loud, quiet, high pitched and low pitched

What is energy?

Energy can exist in many forms, for example:

The units for energy are:

Energy cannot be c _ _ _ _ _ _ or d _ _ _ _ _ _ _

Energy can be transformed from one type to another type

Forms of Energy

Renewable EnergyEnergy from the wind

Energy trapped inside a particle

Energy from the movement of the sea

Energy from the sun

Energy from falling water

Heat energy from inside the earth

Energy from rotting vegetables

Energy Conversions

Practical: Energy Conversions 1. Swinging Pendulum

Pull the pendulum to one side slightly and let it swing.

AS THE PENDULUM MOVES DOWN, ……………………..energy changes into ……………………..energy.

2. Bulb lit by a cell.

IN THE CELL…………………………….energy changes to ………………………….

IN THE BULB…………………………….energy changes to …………………………. and …………………………………..

3. Motor As the motor spins faster and faster, …………………………energy is changed to ………………………….. and …………………………… and …………………………….

4. Jumping Toy As the toy pushes itself off from the bench……………………………….. is changed into …………………………..

As the toy rises in the air ……………………………. Is changed into……………………….

5. Hand-powered Generator

As you turn the handle ……………………………stored in your muscles changes to

………………………….. The generator converts ……………………. energy into…………………. energy.

6. Tuning fork. – Tap the fork on the cork to make the fork vibrate. Hold it

near you ear.

…………………………….energy of the moving arms is converted to

…………………………………( which you hear ).

7. Candle

……………………………….energy in the wax is converted into

…………………………….. and ………………………………when the wax is burnt.

8. Loudspeaker.

………………………………….energy in the wires is converted to ………………………………… energy which you hear.

9. U-track.

The marble had …………………………energy at the top of the track. This changed to

………………………… as it rolled down.

10. Solar powered fan.

…………………………….. from the light bulb is converted to ………………………………….

energy by the solar panel.

The ……………………………energy from the solar panel is converted to

……………………………. of the moving fan.

Questions: Energy Conversions

Glossary of Investigation TermsWord MeaningIndependent Variable The thing that you change in an experiment. There should only

ever be one independent variable in an experiment! This goes in the left hand side of the results table and is plotted on the x-axis of a graph.

Dependent Variable The thing that you measure in an experiment. This goes in the right hand side of the results table and is plotted on the y-axis of a graph.

Control Variables The things that should stay the same in an experiment because they could affect the results if they were allowed to vary.

Categoric Data Data which falls into groups, e.g. eye colour, genderContinuous Data Data which can be measured or counted, e.g. height, weight,

number of peopleFair test An experiment where only one thing (the independent

variable) changes, and all the control variables are kept the same.

Hypothesis A statement to explain why something might happenPrediction A statement to say what might happen in future experiments

based on a hypothesisRepeatable A measurement is repeatable if you can get the same result

twice using the same method and equipmentReproducible A measurement is reproducible if another scientist can get the

same result as you using different methods or equipment.Anomaly / Anomalous result

A result that does not fit the general pattern. E.g. “2, 3, 2, 4, 10, 3” - 10 is an anomalous result because it is significantly different from the rest of the data.Anomalous results should be left out of a mean.

Roller Ball Investigation!Aim:An investigation to see if the height of the roller ball affects the distance moved by the target ball.

Independent variable (1 mark)

Dependent variable (1 mark)

3 Control variables (3 marks)

Hypothesis (use scientific language to explain what you think will happen and why) (2 marks)

How will you make your results reliable? (2 marks for saying how you will do it, 2 marks for actually doing it and showing you have in your results table)

Name one safety hazard in this experiment and say what you will do to reduce the risk of it harming someone (2 marks)

Graph: What type of graph will you draw and why did you choose this type of graph? (2 marks)

Results table (3 marks)

Conclusion – what did you find out? What pattern do you see? (1 mark)

Graph (4 marks)

Useful and Waste EnergyDevice Input energy Useful output

energyWaste energy

Motor spinning.

Torch

Wind-up toy

Loudspeaker powered by a signal generator

Microphone

A candle powering a windmill

A windmill powering a bulb

Jumping Toy

Light Bulb Investigation!Aim:An investigation to see which type of light bulb releases the most waste heat energy.

Independent variable (1 mark)

Dependent variable (1 mark)

3 Control variables (3 marks)

Hypothesis (use scientific language to explain what you think will happen and why) (2 marks)

Name one safety hazard in this experiment and say what you will do to reduce the risk of it harming someone (2 marks)

Results table (3 marks)

Graph: What type of graph will you draw and why did you choose this type of graph? (2 marks)

Graph (4 marks)

Conclusion – what did you find out? What pattern do you see? (1 mark)

Light Energy

How do we see objects?

Reflections

The object is the actual object and the image is what we see in a mirror

Compared to the object, the image is:

1)

2)

3)

Reflections

Rule about reflections:

Why can you see your face in a mirror but not the wall?

Questions: Reflections

RefractionRefraction means bending of light

When light travels from a less d _ _ _ _ area to a more dense area it s _ _ _ _ down and bends t _ _ _ _ _ _ the n _ _ _ _ _

When light travels from a _ _ _ _ dense area to a less d _ _ _ _ area is speeds up and bends a _ _ _ from the n _ _ _ _ _

Questions: Refraction

DispersionLight is _ _ _ _ _. It is a mixture of 7 colours.

These 7 colours are called the _ _ _ _ _ _ _. When white light is split into the colours of the spectrum, this is called _ _ _ _ _ _ _ _ _ _.

Mixing Colours

Seeing Coloured ObjectsThe girl sees a blue car The boy looks at a green leaf

The dog looks at the orange The girl looks at the yellow chick

The man looks at the violet book The girl looks at the black bird

The man looks at the white snow-man The boy looks at the pink flower

SoundActivity What I found out

A

Tuning Forks

B

Elastic Bands

C

Ruler

D

Straws

E

Test tubes

F

Loudspeaker

Sound is caused by v _ _ _ _ _ _ _ _ _

Sound travels like a w _ _ _

A machine called an oscilloscope will show us the wave patterns

Sound can travel through a s _ _ _ _, l _ _ _ _ _ or a g _ _.

Sound cannot travel through a v _ _ _ _ _.

Sound travels faster when the p _ _ _ _ _ _ _ _ are closer together (s _ _ _ _)

Sound is passed on when p _ _ _ _ _ _ _ _ bump into each other.

Amplitude

Frequency

Questions: Sound