Unit 3F: Light and Shadows

Unit 3F: Light and Shadows

Light and Shadows

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Unit 3F: Light and Shadows

Unit 3F: Vocabulary

Useful Words

Transparent

Opaque

Shadow

Block

Direction

A material that light can pass through, a good example is glass

A material that light cannot pass through, a good example is wood

A dark area formed when light is stopped by an opaque object

To stop, an opaque object blocks light

The way something travels

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Unit 3F: Shadows: L.O. 1, 2: N.C. 4.3b

Unit 3F: Shadows

Why is a shadow formed?

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Unit 3F: Shadow Investigation: L.O. 1, 2: N.C. 4.3b

Unit 3F: Shadow Investigation

Shadow Investigation

Investigate the shadow formed on the screen. Can you change it’s size or anything about it? How can you do this? Write down anything you discover.

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Unit 3F: Shadows from the sun: L.O. 3, 4, 5, 6,7, 8, 9: N.C. 4.4b

Unit 3F: Shadows from the sun

Shadows from the sun

1. What will the shadow look like at different times of the day?2. How will you check this?3. Why does the shadow change as you have described?

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Unit 3F: The sun 'moving' across the sky: L.O. 10, 11: N.C. 4.4b

Unit 3F: The sun ‘moving’ across the sky

The sun ‘moving’ across the sky

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Unit 3F: Shadows: L.O. 12: N.C. 4.3b

Unit 3F: Shadows

Shadows

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Unit 3F: Does the sun move on the same route every day?: L.O. 13, 14: N.C. 4.4b

Unit 3F: Does the Sun move on the same route everyday?

Investigation:Does the Sun move on the same route everyday?

This ‘investigation’ will take a number of days to complete. At 9:00 mark on the window the position of the sun. Repeat this at 10:30, 12:00, 13:30 and 15:00. You then need to repeat this process for a total of at least 3 days.

Why is it important to view the position of the sun from the same view point every time?

What do the results tell you?

WARNING: NEVER LOOK DIRECTLY AT THE SUN!

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Unit 3F: Shadow Sizes: L.O. 15: N.C. 4.4b

Unit 3F: Shadow Sizes

Investigation: Shadow Sizes

This ‘investigation’ will require you to take a number of measurements at different times of the day.Is the sun at the same height in the sky all day?When is it highest?Does the position of the sun have any effect on the size of the shadows it produces?Use a shadow stick to measure the size of the shadow the sun produces at 9:00, 10:30, 12:00, 13:30 and 15:00

What do the results show?Do we need to repeat our measurements?

TimeLength of shadow

9.00

10.30

12.00

13.30

15.00

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Unit 3F: The Spinning Earth: L.O. 16: N.C. 4.4b, 4.4c

Unit 3F: The spinning earth

The Spinning Earth

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Unit 3F: Shadow Clocks: L.O. 17: N.C. 4.4b

Unit 3F: Shadow Clocks

Shadow Clocks

How can the sun dial be used to tell the time? How does it work?

What are the disadvantages of using a sun dial in our climate?

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Unit 3F: Transparent and opaque: L.O. 18: N.C. 4.3b

Unit 3F: Transparent and Opaque

Transparent and Opaque

TRANSPARENT objects allow light to travel throughOPAQUE objects do not allow light to travel through

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Unit 3F: Shadows from different materials: L.O. 19, 20, 21: N.C. 4.3b

Unit 3F: Shadows from different materials

Shadows from different materials

For each of the materials predict whether you think they will form a shadow or not. Test each material and record your observations.

Material Prediction Observation

Acetate sheet

Coloured acetate sheet

Plastic bottle

Fine net

Grease-proof paper

Solid plastic

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Unit 3F: Light and Shadows

Unit 3F:

Light and shadows

Shadows

Sun

Appears to move across the sky

Highest in sky at midday

Shortest shadow

Does not move but earth spins

Shadow formed by sun

Can tell approx time

Length

Position

Change over a

day when sun

forms them

Similar in shape to object

Formed when light is blocked

Materials

Opa

que

Translucent

Transparent

Block light

Form Shadows

Lets light through

Some light gets through

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