FEATHERSTONE HIGH SCHOOL A Leading Edge School For an X band class you may use ideas of particle model or wave Science Department or.
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FEATHERSTONE HIGH SCHOOL
For an X band class you may use ideas of particle model or wave
A Leading Edge School Science Department
or photon. You ca n also use the
Lesson plan
idea that light is just one of the
Provision:
waves given off by the sun over terms
Teacher information 1) EAL: Spellings of keywords to be learnt Lesson title: Light lesson 1 Resources/Equipment (e- learning): 1) Need Internet access only if doing research on discovery of light theories 2) SEN: pupils to write in the language that they know the spellings of keywords if required to learn to pronounce Technicians list: given at the end Role of TA: Task 1 Class set – objects that are opaque transparent and translucent, source of light, using a light meter to check intensity of light.
Task3: 250ml beaker, 25ml milk in t-tube, pipette, glass rod, marker pen, 1) To look at resource before the actual lesson in PPA mtg 2)Help in choosing Q to answer
09:06
Physics Unit Code: 2 Lesson number: 1 Lesson Title: How does Light travel?
Learning Outcomes Task 1: I can explain how I see objects and I know what is light.
Level 4 Task 2: I can group material into transparent, translucent and opaque and explain how light is scattered in each scenario Level 5 How I did
I am working at grade .....because ...............................
.......................
I am working at grade .....because ...............................
.......................
Task 3: Explain how light can be scattered when it is passed through a translucent object Level 4-7
I am working at grade .....because ...............................
.......................
Targets I can move up to grade…... by
Recall: Write down names of 3 luminous objects
I can move up to
property made you choose the objects for the above Q?
I can move up to
Challenge: Why is a shadow formed below a luminous object?
New Information for Task 1
• List 5 objects that give out light Laser, fire, sun, bulb, firefly • These are luminous In the first task we will look at: How do we see objects that do not give out light?
Look at the diagram given after the Homework task – then answer the question Then do an investigation related to task 2
Extended Learning
•
On the net go to - iop activities - video light .
Watch the video (it is what you should have done in primary school) • •
In your book write 3 things that you feel were the most important (and you understand these) Or 3 things that you would like to learn more about in this topic
http://www.iop.org/activity/outreach/resources/pips/topi cs/light/page_43036.html
If you know your basics then answer this Q: what is white light made of?
• Due date: Next lesson
09:06
BIG picture
• • • • • •
Key Question: How does light travel?
What skills will you be developing this lesson?
Scientific Investigation- collecting primary data and recording in various ways Literacy- by writing well structured sentences and paragraphs Personal skills- team work, leadership Thinking and Learning- organisation, logic, participation, exploration, judgement, planning, practice.
Reflection- through self or peer assessment of each Learning Outcome
•How is this lesson relevant to every day life?
•
Understanding everyday phenomenon - why can I see objects during day and at night
•
Lasers, holograms!
•Quick Discussion: •What do you already know?
09:06
Keywords:
Trans parent Trans lucent Op a que Reflect Investigation Hypothesis Dis persion Trans mission
Here are some of the words we will be using in this lesson, check what you can do 1) Learn the spellings (quickly go over the spellings 3-5 times, cover the word and check if you have got the spelling/ ask your partner to test you) Extn: Create sentences which use the keywords correctly. 2) Put your hand up if there is any key word from the list that you don’t know the meaning of.
09:06
New Information for Learning Outcome 1
Explore and Discover:
• Visual: Demo of experiments showing path of light • Audio: In this Unit we will look at how light travel – is it as a wave, a ray or a stream of particles? Is it a single color or many colors mixed together? Does it have a frequency like sound? And what are some of the common properties of light, such as absorption, reflection, refraction and diffraction?
• Kinaesthetic: Do some experiments to show the properties and uses of light 09:06
New Information for Learning Outcome 1
How does light from a light bulb or other light sources reach your eye?
L
uminous
objects give out light and can be called a light source.
Seeing a luminous object
Light travels in a straight line directly
inside
your eye.
Seeing a non-luminous object Objects that do not give out light are
non-luminous
.
How does your eye see
non-luminous
objects such as a book?
Light from the light source strikes the book and some of the light is reflected from the book into your eye.
Task 1
• Draw a diagram to show how the light gets into the eyes to see the flowers, look at the next slide
Task 1
Simplistic drawings for ray diagrams
1.
2.
3.
Draw a straight line starting from the sun going to the flower(imp: it must touch the source and object) Continue the line from the flower to the persons eye (light goes into the eye-so the line must touch the eye) Draw an arrow on each of the line showing the direction it is going in.
New Information for Learning Outcome 1
What is light and sight?
Ibn al-Haytham, who lived in present-day Iraq between A.D. 965 and 1039 identified the optical parts of the human eye. He correctly described vision as a process involving light rays bouncing from an object into a person's eye Some of the brightest minds in the history of science have focused their thought on the subject.
Albert Einstein tried to imagine what it would be like to ride on a beam of light. "What if one were to run after a ray of light?" he asked. "What if one were riding on the beam? …
Early history of discovery of light
09:06 http://www.youtube.com/watch?v=iletCKDCt_0&feature=related
New Information for Learning Outcome 1
Brain storm – in pairs How does the energy as light from the SUN reach us?
Beam, Particle, small packets, like water waves?
Choose one and discuss in pairs pros and cons – your first thoughts – 2/3minutes 09:06
New Information for Learning Outcome 1
Here are some things to think about: • Our brains and eyes act together to make extraordinary things happen for us to see. Movies are sequences of still pictures. Magazine pictures are lots of dots.
• Light acts like particles—little light bullets—that stream from the source. This explains how shadows form.
• Light also acts like waves—ripples in space—instead of bullets. This explains how rainbows work. • In fact, light is both. This "wave-particle duality" is one of the most confusing —and wonderful—principles of physics.
09:06
New Information for Learning Outcome 1
If Light is a wave then are there other waves coming from the sun? The answer is YES!
All the waves given below come from the sun, but we can ONLY SEE some of the ones called LIGHT. In year 7 we will talk about light as if it were a wave. The light as we see is made of various colours.
Can you name any of the waves?
09:06
New Information for Learning Outcome 1
In fact it is a mixture of colours that make the white light
New Information for Learning Outcome 1
Light travels in a straight line and then when it hits an object it gets: 09:06
Learning Outcome 1: Review
Go back to your Learning Outcome grid and fill out the ‘How I did’ and the ‘Targets’ column.
Learning Outcome Learning Outcome 1: I can explain how I can see things and know what is light How I did Targets
I am working at grade .....because ...........................
...........................
I can move up to grade…... by …………………… …………………… Grade C 09:06
New Information for Learning Outcome 2
•
Explore and Discover:
Visual: Observation of demo of various transparent, opaque and translucent objects
•
Audio: Discussion – how do some materials allow light to pass through, could we see behind non transparent objects
•
Kinaesthetic: Using a light meter to check light levels through various objects
09:06
New Information for Learning Outcome 2
Different forms of matter can 1.
Absorb the light waves, 2.
Change the direction of the waves, 3.
Allow the waves to pass through without alteration!
If a material absorbs the waves of visible light, we can’t see through it, like wood. If it allows visible light to pass though it, it will be like glass. However, even glass is not completely see through, it does absorb some light and also changes the direction of the light to some degree.
However
A new experiment conducted by scientists has shown that it's possible to see through opaque materials and detect objects hidden behind them.
http://www.dnaindia.com/scitech/report_new-experiment-shows-how-to-see through-opaque-materials_1357071 09:06
New Information for Learning Outcome 2
• Task 2: • Look at the range of objects and group them • Group them again, using light as a way of grouping • Now place them in 3 groups • Give the groups a name • Task 1: Extension • Live text page 88 interactive animation answer questions (Icon with the hand symbol)
Keywords for Task 2:
•
light
•
reflect
•
bright
•
object
•
transparent
•
Translucent
•
Opaque
Task 2: Answers
Demonstrate your Learning for Outcome 2 Intensity of light and circle formed from a torch as seen from 8, 10, 20, 30, 40cm distance Create Evaluate Which task(s) will you choose to complete? Try to target a grade higher than your current grade.
Graph showing light intensity against distance
Understand Remember Keywords: Transmit, absorb, reflect, opaque, wave, particle, Evaluate (7) Hypothesis for the expt on left : Light intensity decreases with distance. Does the observation and graph on left justify the hypothesis?
Understand (5) Explain using keywords how light is reflected off a mirror Remember (3) Write 4 sentences to describe what you saw in the experiment. Take care to spell keywords correctly. In the first experiment I saw how …….
Task 2: Answers
Intensity and light When you moved the paper away from the flashlight, the circle of the beam (i.e., the area) became much larger. Because the light output of the beam was constant, the intensity of the beam became much less. So the hypothesis is justified. The graph shows that in fact, as you doubled the distance from the flashlight, the intensity decreased by 4 times. At 5cm it is 36 and at 10cm it is 9 Rules for ray diagrams • Draw straight lines that originated from a source and are reflected off an object and travel into the eye • Touch the source, surface of reflection and eye, draw arrows to show direction of travel
Learning Outcome 2: Review
Go back to your Learning Outcome grid and fill out the ‘How I did’ and the ‘Targets’ column.
Learning Outcome How I did Targets Learning Outcome 2: I can group material into transparent, translucent and opaque and explain how light is scattered in each scenario Grade B
I am working at grade .....because ...........................
...........................
I can move up to grade…... by …………………… …………………… 09:06
New Information for Learning Outcome 3 Explore and Discover:
•
Visual: observing effect on light intensity when milk is added to water
•
Kinaesthetic: Expt to be done as a demo if there is no time to do the investigation
09:06
New information task 3
• Sometimes we want glass to let the light in but not let people see in. Bathroom windows use obscuring glass. The trick is to allow the light through but to mix up the information the glass carries. This can be done by scattering the light rays.
• Scientists often use a model before starting experiments that use more expensive equipment. Here you will be using water and milk to model scattering by obscuring glass.
• Hypothesis
As I keep adding milk to water the amount of light passing through will gradually decrease and then no light will pass through
New information task 3
New information task 3
1. Put 250 ml of water into the beaker.
2. One pupil secretly draws a letter about 2 cm high on a piece of scrap paper.
3. That pupil then puts the letter behind the beaker against the glass so that it can be seen through the water, as shown in the diagram above.
4. The other two pupils make a note of what letter they think they can see through the water.
5. The three pupils compare letters. If they are all the same, add five drops of milk to the water, stir, and try with another letter. Keep the letters the same size and thickness as the first letter. Continue, keeping a note of how many drops of milk have been added.
6. Continue this process until the letters do not agree.
7. Repeat the experiment twice more starting with fresh water each time.
8. Repeat the experiment one more time, but stop adding milk just before it starts to get difficult to read the letter, now move the letter backwards away from the beaker, what do you notice?
Results
Number of drops of milk All 3 agree on the letter?
You can do this as a class, group one uses 10 drops & 20 drops group 2 uses 30/40 drops …………………….
Task 3 (Level 4-6)
Discuss in pairs: Was your hypothesis correct? What did the experiment prove? Use as many keywords in your discussions as you can to give reasons for the milk obscuring the light.
Use words like because and however for explaining and comparing
Keywords for Task 3:
•
Reflect
•
Light
•
Bounces
•
Transparent
•
translucent
•
Opaque
•
Solid
•
Liquid
•
Particles
Task 3: Review
Go back to your lesson outcome grid and fill out the ‘How I did’ and the ‘Targets’ column.
Lesson Outcomes Task 3: Explain how light can be scattered when it is passes through a translucent object Level 4-7 How I did Met?
Partly met?
Not met?
Targets How can I improve on task 3?
Review
Match each word to a definition.
1
transparent
2
opaque
3
translucent
4
absorbs
5
emits
6
reflects you cannot see clear images through it you cannot see clear images through it
Review of lesson
Demonstrate your Learning for Outcome 1
•
Keywords: reflection
•
light, reflect, Bounces
•
Transparent, translucent
•
Opaque, Solid, Liquid Remember (3) Write instructions for a class to do the experiment Create Evaluate (7) Recommend improvements to your investigation Apply (5) Describe the difference between the way that the milk scatters the light and the surface unevenness scatters the light.
Evaluate Which task(s) will you choose to complete? Try to target a grade higher than your current grade.
Analyse (6) Many types of obscuring glass are not frosted, but have a wobbly surface. Describe how this does the same job. Would this sort of glass be suitable for a bathroom screen?
Understand Remember Understand (4) Did your experiment demonstrate the hypothesis you made at the start? Give reasons for your answer as a conclusion for the experiment
Task 3: Answers
Evaluate (7) Improvements to the investigation: Collect as many readings as possible 7-8, compare with others (secondary data) , measure the volume using a burette, take reading with close intervals, use a light intensity meter to check readings, cover the meter so no external source of light falls on the meter.
• Analyse (6) The uneven surface refracts the light in unpredictable directions to confuse the information it carries. The milk droplets act like tiny ball-shaped mirrors to change the direction of the light.
• Apply (5) The surface unevenness makes the light leaving the glass change direction at the surface. This ‘confuses’ the light, and makes it impossible to make out details of objects viewed through the glass.
•
Understand (4)
The experiment results do confirm my hypothesis as the intensity of light decreased as I added milk to the beaker. The reason for this could be that the concentration of milk in water was becoming more and the light was either being reflected back or being absorbed by the milk particles
Outcomes for Task
• •
Answers L5 (reasons given) Considering the evidence
• Experiment 1 shows that light can travel through the rubber tube
but not if it bends
.
• Experiment 2 shows that the hole in the card must line up for light to pass through three of them.
If it could travel in a curve,
holes as well.
it would shine through the other set of • Experiment 3 shows that light travels in straight lines
otherwise it would bend round the card
and fill-in the shadow area, and it doesn’t.