Yr+7+Light+heat+and+sound


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Forms of energy Conversion of energy Heat energy and how it is transferred Light energy and how it travels Sound energy and the nature of sound waves || ** 4.1 ** Forms of energy: - Heat, Light, Sound - Electrical, Chemical, Nuclear - Kinetic, Gravitational, Elastic Inefficient/efficient Fossil fuels || ** 4.2 ** Heat Temperature Conduction Insulators Convection Radiation Electromagnetic Absorbed Reflected Transmitted || ** 4.3 ** Luminous Non-luminous Incandescent Bioluminescent Shadows Umbra Penumbra Reflection Real and virtual images Inversion || Concave Inverted Focus Convex || ** 4.4 ** Sound wave Echo Sonar Radar Reverberation Resonate Amplify ||
 * Key Concepts |||||| Vocabulary ||  ||   ||
 * What is energy?

** Priority ** Releasing the sun’s energy (p. 93) || Energy changes (p 32-3) || Revision (p. 91 Q 1-9) Thinking (p. 92 Q 10-13) || Science at work activities (p. 92) || Conductors worksheet || Comparing materials (p. 102) Comparing metals (p. 103) Conduction in water (p. 103) Insulators (p. 104) Convection currents (p. 104) Radiation emission (p. 105) Radiation absorption (p. 105) || Other temperature scales (p. 34-5) || Revision (p. 100 Q 1-13) Thinking (p. 100 Q 14-18) || Science at work activities (p. 101 & 102) || Animation: [|http://psy2.ucsd.edu/~sanstis/Foot.html] (see ‘Step Through Time’ Prac for Explanation) Light stations activity/pracs Law of reflection teacher demonstration || Light stations activity/pracs The pinhole camera (p. 113) The law of reflection (p. 113) Image location (p. 114) The periscope (p. 115) Making rainbows (p. 115) Curved mirrors (p. 116) || Applications of laser light (p. 36-7) || Revision (p. 110 Q 1-14) Thinking (p. 101 Q 15-19) || Science at work activities (p. 112) || Research Task || Sound in a vacuum (p. 123) A sound cannon (p. 123) The speed of sound (p. 124) Measuring cylinder resonance (p. 124) || A sonic wave generator (p. 38) Morse code (p. 39)
 * || Activities || Pracs || Homework Book || Questions from text book || Extension and variations ||
 * ** 4.1 Energy ** || Forms of energy mix & match || Chemical energy (p. 93)
 * ** 4.2 Heat ** || Heating role play
 * ** 4.3 Light ** || Tracing objects using a mirror
 * ** 4.4 Sound ** || Sound worksheet

Greek theatre

http://www.sciencedaily.com/releases/2007/04/070404162237.htm || Revision (p. 121 Q 1-14) Thinking (p. 121 Q 15-21) || Science at work activities (p. 122) || Sci-words (p. 41-43) || p. 125 Qs 1-25 ||  || Test ||
 * ** Revision ** ||  ||   || Heat, Light & Sound Crossword (p. 40)
 * ** Assessment ** |||||||||| Research Task

=Heat and conduction=

The spoon experiment
Draw a picture of the spoon experiment _ label the different spoons and the glass beads

Which one conducted heat best? The metal spoon. How did you know? The glass bead fell off this spoon first because the wax melted.

Which ones would be good insulators? wood and plastic because they don't conduct heat very well. The wax did not melt and so the bead stayed on the spoon.

The metal rod experiment
Draw a picture of the metal rod experiment. - Label the different types of rods and the glass beads

Which one conducts heat the best? Copper conducts heat best.

What happens when heat is conducted? For heat to be conducted each atom has to start vibrating until it bumps into the atom next to it. When it does this the Energy (heat) is passed on. In an insulator the atoms are held so tightly that they can't vibrate much and pass the heat energy on to the next atom.

Method:
set up as shown Each member of the team will need to trace the mirror and the ray box on a page in their book. Plot the light rays path as it is reflected off the mirror.

Results
Sample results from the class incoming ray ||~ Angle of Reflection outgoing ray ||
 * ~ Trial ||~ Angle of Incidence
 * = 1 ||= 30 ||= 31 ||
 * = 2 ||= 62 ||= 61 ||
 * = 3 ||= 18 ||= 18 ||
 * = 4 ||= 35 ||= 35 ||

Conclusion
The Law of reflection states… Our results show that this is true on most cases but sometimes we are 2 or 3 degrees out. In this experiment this is an error due to the thickness of our pencil. So we could say that our experiment upholds the law of reflection.

All about Light
Light is a form of energy. To explain its properties we say its energy travels in waves. These waves travel in straight lines. This is why we can't see around corners.. Light can be reflected, refracted, dispersed and scattered.

When light is reflected from a plane mirror (flat mirror) we can see our image at about the distance behind the mirror as we are in front of the mirror. We know there is no real person inside the mirror - but we call this image a virtual image.

An image that can be projected onto a screen is called a real image. You can do this with curved mirrors. Curved mirrors can focus light to a point. The lens in your eye focusses light on to the retina of your eye so you can see clearly. If it is not clear you need glasses. These lenses correct the focussing of your lens.

There are two types of mirrors. 1. A concave mirror - has a dip in the centre. They can produce an upright enlarged virtual image when the object is up close OR an inverted real image if the object is further away.

2. Convex mirrors - are bowed out at the centre and are used in shops and intersections to observe what is coming along. They produce a smaller virtual image behind the the mirror.

Exploring the concave mirror
draw the image that was projected onto the screen, draw the position of the candle and the mirror.

Was it a real image or a virtual image? Was it right side up or an inverted image.

Exploring the convex mirror
Turn the mirror around and try the experiment again - can you project an image? Can you see an image in the mirror?

Making a rainbow
Draw a labelled diagram of the equipment you used to make a rainbow. label the colours of the rainbow. What other ways are there to make a rainbow?

Questions from text p 110 Q 2, Q8, Q11, Q13 Q17, Q20, Q21

The speed of light http://speedoflight2012.org.uk/ [|More about calculator.] ||
 * ||  || == **the speed of light = 299 792 458 m / s** ==

the speed of sound

http://www.physicsclassroom.com/class/sound/u11l2c.cfm

Sound
Sound is a form of energy. Sound needs something to travel through, unlike light. While light can travel through a vacuum sound can not. Some movies show explosions in space that are very loud BUT this is not accurate. Because there is nothing for the sound energy to travel through - there would be no noise.

When we examine sound it is made of vibrations. The sound energy makes air particles vibrate and bump into the particles next to them. Different sounds cause different patterns of vibration. The patterns in the air make some parts compressed and other parts spread out.

Types of waves
Sound is an example of a longitudinal wave - the particles move back and forward as the energy is passed along.

Another type of wave is a transverse wave - the particles move at right angles to the direction of the wave ie up and down like a water wave.

Speed of sound
Depending on what the sound is travelling in the sound wave will have a different speed. In air at room temperature (20degrees Celsius) it should travel at 343m/s. At 0 degrees Celsius it travels at 330 m/s and in water it travels at 1400 m/s but in wood it travels at 4500 m/s

How does density of a substance affect the speed of sound travel? The Greek AmphiTheatre was a marvellous structure that enabled the audience to hear the spoken word from the back of this immense theatre. Many researchers came up with the idea that the shape was the main reason for the ability of the theatre to amplify the sound. however read this to find out what they think really made the sound carry. http://www.sciencedaily.com/releases/2007/04/070404162237.htm

Draw and label your string and cup phone. Why did it work? When did it not work?
 * Making A string and cup phone**

Sound Questions Revision (p. 121 Q 1, 2, 6, 7, 9, 10, 12, 13, 14) Thinking (p. 121 Q 15, 17, 19, 21 23, 25 )