Light Banner 2018

2018 Stage3 T3 - LIGHT (Physical World)

FIXME - Not yet done - Coming Term 2 2018

REVISION: With reference to the ST3T1 ELECTRICITY wiki page, What do you think is the difference between 'Light' and 'Electricity'?

OUTCOMES

A student:

CONTENT

Electrical circuits

Energy from a variety of sources

Light from a source

UNDERSTANDING LIGHT: FLIPPED CLASSROOM

FLIPPED CLASSROOM is a form of blended learning in which students learn content online by watching video lectures, usually at home. What used to be called 'homework' is now done in class with teachers and students collaborating, discussing and solving questions.

In a 'flipped' project, teacher interaction with students is more personalised. The emphasis is on guidance and mutual discovery rather than lecturing. More information and resources are available for teachers in the WPS Teacher WIKI.

The starting point for this particular 'flipped' activity is an on-line science QUIZ:

IT IS IMPORTANT THAT STUDENTS & TEACHERS FIRST COMPLETE THE LIGHT QUIZ BEFORE VIEWING THE STUDENT WIKI (THIS PAGE!), THE FLIP CONTENT OR THE TEACHER WIKI CONTENT.

Light - An introduction:

Reflection:

Have you ever thrown a rubber ball at something?

If you have, you know that when the ball hits most things, it bounces off them.

Like a rubber ball, light bounces off most things it hits - Light is made up of lots of things that bounce.

  1. When light falls on something, mostly, it is like a hand-full of rubber balls being thrown - not just one ball.
  2. When light travels to something opaque, some of this light stops there - BUT, some of this light bounces off.
  3. When light travels to something translucent or transparent, most of the light passes through - BUT, some of this light bounces off.
  4. When light bounces off things and travels to your eyes, this information is passed to your brain and you are able to see. 1)

When light bounces off of things, scientists call this reflection

To explain how light travels and bounces off of things, scientists use 'ray diagrams'.

A ray diagram is a drawing with arrows that shows where the light is coming from, what it is hitting, and where it travels after it bounces off of something - detailed science resources from lightandmatter - Read more...

Light Travels from the sun & objects

Fig 1. Two Ray Diagrams: How Light Travels From The Sun & From Objects


WARNING: NEVER LOOK INTO THE SUN, OR A LASER OR ANY OTHER BRIGHT LIGHT


Experiment #1:

This experiment will show what happens when light shines through a small hole onto a wall.

MATERIALS:

PROCEDURE 1:

OBSERVATIONS:

PROCEDURE 2:

RESULTS:

Draw a ray diagram showing how the light travels from a torch, through a small hole and onto a wall.

Below the ray diagram, draw what you saw for each size hole and add labels to show what you saw.

Q 1. How can you find out where the light that falls on the wall is coming from?

Q 2. Can you think of an experiment to show that light bounces off something in the same way that a ball would bounce off the same thing?

DISCUSSION:

Is there any difference between what you see on the wall when you compare when light shines through the small hole compared with when light shines through the larger hole (write down what you think)?


Video 1. Does the size & shape of a hole affect the light passing through it?


Opaque Objects (things that block light):

Video 2. Opaque Objects & Shadows

If you have time, cut out your own animal shapes using cardboard and find a dim room. Use a torch to make shadows of your cardboard cut-outs and see what happens to the shadows when you move things around. If you have a dark room and a lamp, you can even put on a shadow play using your hands, or make your own shadow puppets


QUESTION 1. LIGHT - True or False?

If you were to turn off the room lights for a moment and then cover all the windows with black paper so that absolutely no light can enter, do you think that you would still be able to see anything in the room?

And so, what do we see when we see black?

When we see 'black', we are not seeing a colour, it is simply the absence of light - Do you 'see' what that means?!

To put it another way: When a room full of objects (or a table, a shirt, a chair or a sky) looks black, then it is because those objects are not generating and/or reflecting light into your eyes.

So, without light, do you think you would you be able to see anything?

Source: 2)


Introduction To The Physics of Light:

Video 3. Refraction & Colours Explained

CLASSROOM ACTIVITY: Complete a 'marching soldier analogy' experiment


References

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1)
Blecha, Gega, & Green, 1979, p. 154