Year 8 Science Light and sound Name: My last test result My Target

8K Light Level 3 I know that different materials let different amounts of light through. I know that materials that stop light cause shadows to form. I know why objects look dark. I know that some objects reflect light. I know that shaped glass can make rainbows from white light. Level 4 I know that light travels in straight lines unless something is in the way. I can describe what happens to light when it hits different materials using scientific words. I know that white light is made up of a mixture of colours and how to split white light into its colours. I can explain why we see lightning before we hear thunder. I can describe the reflected image in a plain mirror using scientific words. I can describe some ways that colour is important in everyday life. Level 5 I know the role of reflection. I can explain how we see objects. I can explain why objects appear to be different colours. I know that all colours are made from 3 primary colours. I know that filters can absorb some colours and reflect others. I can draw the path of rays of light as they are reflected. Level 6 I know that light bends as it passes from one material to another. I can explain why this happens by using a ‘model’. I can draw the path of rays of light as they are refracted. Level 7 I can relate how shiny a material is to how much light reflects from it. I know that different colours refract by different amounts and I can show this in an experiment. I can use the speed equation to calculate how long it takes light to travel certain distances. I can explain the appearance of coloured objects in different coloured light.

8L Sound and hearing Level 3 Expectations  Sound and Hearing Level 3 I know that sound is caused when things vibrate. I know that the vibrations happen at different speeds – sometimes too fast to see. I know that sound can be reflected. Level 4 I can describe how the speed and size of the vibration changes the sound when I do an experiment. I know that sound travels through solids, liquids and gases, but not through a vacuum. I can explain why we see lightning before we hear thunder. I can describe how we hear sounds. I know that loud sounds can damage our ears. Level 5 I can explain pitch and loudness in terms of vibration. I can explain why sound cannot travel through a vacuum. I know that sound can be represented by an oscilloscope trace. Level 6 I can relate loudness and pitch to vibration, using the words amplitude and frequency. I know the range of human hearing. I know that sound travels at different speeds in different materials. I can explain how the ear works and why loud sounds damage our hearing. Level 7 I can explain sound as a wave. I can explain how sound travels using particle theory. I can relate my knowledge of particle theory to how the ear works. I can explain the causes of permanent and temporary deafness.

8K/L Seeing Things Some object make their own light and some objects reflect light. Draw arrows to show how light has travelled to the girl’s eyes to let her see: the Sun traffic light the tree her friend

1a 8K/L Mirror Angles 1 Place a mirror on the back of this sheet of paper and direct a ray of light towards the mirror Use TWO crosses to mark in the position of the light that goes TOWARDS the mirror. Use TWO crosses to mark the position of the light REFLECTED from the mirror. Draw a pencil line across the BACK of the mirror. Join up the dots and crosses to the line that marks the back of the mirror. ray normal

8K/L Mirror Angles 2 Hitting Angle Reflecting Angle 1b Use a PROTRACTOR to measure the ‘HITTING ANGLE’ and the ‘REFLECTING ANGLE’ 7. Write your results in the table below: 8. Repeat the experiment shining light in at different angles. 9. Is there a pattern between the HITTING angle and REFLECTING angle? _____________________________________________________ Hitting Angle Reflecting Angle

8K/L Light Travels Match each explanation to a picture..

Light Changing Direction 8K/L Light Changing Direction You will be asked to place a glass or plastic block onto the rectangles on the next page. (Have a look at them now) Shine a thin ray of light into the block as shown on the diagrams. Use a pencil to make two crosses so that you can draw the path of the ray. (An example of this is shown below) A B x x x x Repeat for each of the rectangles shown on the next page. Answer the questions below: Does light ALWAYS change direction when it passes through the block? ______________________________________________________ 2. When does the light NOT change direction? _______________________________________________________ 3. When the light DOES change direction, can you describe HOW it changes?

2b 8K/L Rectangles Sheet 1 Place the glass or plastic block on the rectangles. Shine a thin ray of light into the block in the direction of the arrow Use a pencil to mark the path of the light ray.

2c 8K/L Rectangles Sheet 2 When light passes from air into glass or plastic it ________________. This slowing down of light is called _________________ When light is slowed down it sometimes changes direction

3a 8K/L The Coin Trick This trick uses the effect of REFRACTION. This is the word we learned about last lesson. Refraction is when light gets SLOWED DOWN as it passes through an object like glass or plastic. Put a coin in the bottom of a cup. Use a piece of Blu-tack to hold it in place. Move the cup away from you until the edge of the cup just hides the coin. Get someone to stand in your place and look at the cup. Tell the person you can make the coin appear just be adding water to the cup. Slowly add the water to the cup to see if the coin appears. Write down how you can explain the trick using REFRACTION ___________________________________________________________

Splitting white light into colours is called DISPERSION 8K/L White Light Spectrum Place a triangular prism on a piece of paper. Shine a light ray towards the prism as shown in the diagram below: Turn the prism slightly until you get the best possible range of colours. Draw what you see ON the diagram ABOVE. Can you explain how DISPERSION is caused by REFRACTION ______________________________________________________ Splitting white light into colours is called DISPERSION

8K/L Colour Filters 3d Colour of Filter Colours that pass through Use a triangular prism to make a spectrum. Place different coloured filters in the path of the spectrum. Use the table below to show which colours PASS THROUGH the filter and which colours are ABSORBED (do not pass through) What did you discover about the filters? ______________________________________________________ Colour of Filter Colours that pass through Colours that are absorbed

White Light Spectrum… Optional 8K/L White Light Spectrum… Optional Collect a piece of card and draw a circle with 6 sections as shown below. Colour the circle in this order RED, ORANGE, YELLOW, GREEN, BLUE and VIOLET 3. Cut out the circle and put a sharp pencil through the middle Spin the disc. What do you see? ____________________________________________________

8K/L Seeing Colours 4c Colour of beam Colour of Object You are going to try and find out how coloured objects appear in different coloured lights. You will use a ray box, red, green and blue filters, coloured objects and white paper. You will need to set up the apparatus as shown below: Place each object in the coloured beam of light and record the colour that it appears. Colour of beam Colour of Object Colour Object Appears

Seeing Colours… Optional 4d 8K/L Seeing Colours… Optional When white light shines on an object the colours in the white light may be ABSORBED by the object or REFLECTED from the object. Can you explain why?_________________________________________ _________________________________________________________ Some people cannot tell the difference between some colours. This is called COLOUR BLINDNESS. Ask your teacher for a colour blindness chart! In this diagram the RED ball looks red because it REFLECTS RED LIGHT but ABSORBS the other colours in the white light. In this diagram the girl is looking at a YELLOW book. The book is REFLECTING red and green light (making it look yellow).

8K/L Light Passing Through Discuss the meaning of these three words. Transparent ............................................................................................................... Translucent ............................................................................................................... Opaque ........................................................................................................................ Label the pictures with the three words above.

8K/L Pitch & Music 6a Watch the demonstration using the CRO CRO means Humans can hear sounds of FREQUENCIES from ____________ to _________ Now go to On Line Learning/Key Stage Three/Year 8/ Light & Sound&Spoons & Tunes Try to make a tune using this program.

6b 8K/L Hearing Sounds Use the words in the box below to fill in the missing word in the sentences about the Ear. Source ears bones vibrations air eardrum inner ear brain nerve Sound travels to our ears from a ______________. The sound is made by _____________________ which causes the ___________ to vibrate. The sound travels as a sound wave to our ____________. When sound enters our ears, the ________________, which is a thin sheet of skin, vibrates too. The vibrations are passed into the inner ear by the small ______________. In the _______________, the vibrations are changed into electrical messages which travel to the brain along a _____________ . When the messages get to the _______________ we hear the sound.

8K/L Loud and quiet Your teacher will show you a device for measuring the loudness of sounds. It is a decibel meter. Measure the loudness in dB of various sounds. A person talking normally .................... dB School bell .................... dB A quiet corridor .................... dB

8K/L Loud and quiet

5a 8K/L Making Sounds When you blow across a pen top or an empty bottle, you can make a sound. This is because the air inside vibrates and makes a noise. If you have different amounts of water in the bottle, you can make different sounds. METHOD Take 5 test tubes and arrange them in a test tube rack. Leave one test tube empty and put DIFFERENT amounts of water in each of the other test tubes. Blow across the top of each test tube. Can you ‘hear’ a difference between the sounds coming from each test tube? Is there a relationship between the length of the air above the water and the ‘pitch’ of the note? _____________________________________________________ KEEP YOUR TEST TUBES TO COMPARE WITH THE NEXT EXPERIMENT

8K/L Making Sounds Again 5b Does the ‘pitch’ of the note depend on the WIDTH of the air column above the water or the HEIGHT of the air column above the water? In order to find the answer to this we have to try another experiment. METHOD Repeat the experiment but this time use BOILING TUBES instead of TEST TUBES. Make sure that the water level is at the SAME HEIGHT in the boiling tubes that they were in the TEST TUBES. Blow over the mouth of each of the Boiling Tubes. WHAT DID YOU FIND OUT? _________________________________________________________

In space no-one can hear you scream… 8K/L In space no-one can hear you scream…

Homework: Light passing through

Homework: Seeing Things 8K/L Homework: Seeing Things

Homework: Sound and light 8K/L Homework: Sound and light In a thunderstorm both light and sound are made at the same time. We see the lightning before we hear the thunder. Explain why? ................................................................................................................ ......................................................................................................................................... ........................................................................................................................................ ....................................................................................................................................... ...................................................................................................................................... Light Sound Find out the speed of sound and the speed of light. Speed of sound = ....................................... Sped of light = .......................................

Homework: Sound Travels 8K/L Homework: Sound Travels

Light and Sound Keywords Meaning