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SCIENCE
Light and Sound
Natural Light• Light made naturally by the sun
Day 1
Artificial Light
• Light originating from a man made source.
• *Light made by a battery or electricity.
Darkness
•Absence of light
Light travels in a straight lines. It can go in all directions from its source, but it goes in a straight path in all those directions.
Day 1 note
1.Light is a form of energy that travels in straight lines.
2.Light and sound are both forms of energy.
3.Light can move through matter or empty space.
4. Light travels in a straight line.
Reflection• Light that bounces off an object like a
mirror or shiny materials• Mirrors reflect light at the same angle that
the light strikes them. This works the same way as a ball bouncing off from a flat surface.
Day 2
Reflection
animated reflection manipulating light (scroll down to 3 rd image)
Day 2 Notes
1.Light travels in a straight line, but goes in all directions from its source.
3. Mirrors reflect light at the same angle that the light strikes them.
4. When a mirror reflects light, it reflects the image.
More Refraction
• When light moves from the air to the water it slows down.
• When a beam of light enters water at an angle, the light bends.
• When a beam of light enters water straight on, it does NOT bend.
• Refracted light can make an object seem to be in two parts
Refraction• The bending of light when it moves
from one kind of matter to another• When light moves from one material to
another it changes speed, this causes the beam of light to bend
Day 3
EXTRA Interesting fact:
Mirages On a hot day, you can sometimes see what looks like a pool of water on the ground – even though the ground is completely dry. In fact, the "pool" is caused by refracted light from the sky. The air close to the ground becomes hotter and, therefore, less dense than the air higher up. This change in density causes light from the sky to be bent upward so that it reaches your eyes from the direction of the ground. The effect is called a MIRAGE and is common on hot roads, in deserts, as well as the sky. Mirages of distant objects on the horizon, such as mountains, may be seen.
COLOR• White light has all the colors of the rainbow in
it.
• The color of an object is the color that it reflects back for us to see, the other colors are absorbed.
Visible Spectrum
• The 7 colors of light that people can see
ROYGBIV
Prism
• A solid object that bends light (refraction)
• As white light enters the prism, its speed changes. The change in speed causes the beam of light to bend.
• All of the colors in the white light have different wavelengths. They are bent at different angles, so that the colors separate.
Rainbows “ERRRE”• Water can act as a prism, producing rainbows
How does this happen?
1. Sunlight enters a raindrop2. The sunlight is refracted as it passes
through the water3. The sunlight is reflected from the
raindrop’s back wall.4. The sunlight is refracted again5. Sunlight exits through the front of the
raindrop
Poems for “Roy G Biv”
Prism in the WindowI wake to light Color falls on colorFalling through glass I hear cymbal soundColors splintering and clashing breaking into rainbow dustIn the air. Shattering
into sevenThe noise of morning sunlightrainbow chimes!Being smashed apart PRISMWakes me
This is my alarm!
Light – Day 3: Reflection and Refraction
1.Light waves are straight or bent, depending on the object they come in contact with.
2. Some of the light energy that hits an object is absorbed.
*Objects of different color absorb different amounts of light.
3. Dark objects absorb more light energy than light-colored objects.
4. Because dark objects absorb more light energy, light-colored clothes keep you cooler on a bright summer day.
5. Objects don’t absorb all the light that hits them. Some of the light bounces off. This bouncing off of light from a surface is called reflection.
6. Light usually scatters in many directions as it is reflected.
7. The bending of light as it moves from one material to another is called refraction.
8. A refracted beam of light seems to as it changes directions.
9. White light has all the colors in the rainbow.
10. You can separate white light into colors by using a glass prism.
.
11. As white light enters the prism, it’s speed changes.
12. The change in speed causes the light to bend.
13. All the colors in the white light have different wavelengths
14. The different wave lengths of white light are bent at different angles which causes the colors to separate.
Absorption• When light hits an object, the object
can absorb the light, make it bounce off, or let it pass through.
• White is ALL colors Reflected• Black is the Absorption of ALL color• Light colors reflect more light than
dark colors, that is why in the summer light colors feel cooler.
Day 4
Light Notes: Day 5
1. Which absorbs more heat - light or dark colors?
2. Black is ALL colors REFLECTED.
3. White is the ABSORPTION of ALL colors.
4. The color of an object is the color that it reflects back for us to see. All of the other colors are absorbed.
Transparent
• Allow light to pass through easily, neither reflecting or absorbing much light
• You can see a clear image when you look through a transparent object
• Leaves NO shadow
Day 5
Translucent
• Objects allow only some light to pass through them
• You can tell that there is something on the other side, but it is not clear. You can only see blurry objects.
• They cast a light or “fuzzy” shadow.
Opaque
• Reflect or absorb all light, do not let any light through
• They cast a dark shadow
• You cannot see things on the other side.
Light - Day 4
1.The following characteristics describe transparent objects.
• They allow light to pass through easily, neither reflecting or absorbing much light.
• You can see a clear image when you look through them.
• They leave no shadow.
2. The following characteristics describe translucent objects.
•They allow only some light to pass through them.
•You can tell there is something on the other side, but it is not clear. You can only see ?? Objects.
•They cast a light or fuzzy shadow.
3. The following characteristecs describe opaque objects.
•They reflect or absorb all light; do not let any light through.
•They cast a dark shadow.
•You canNOT see things on the other side.
4. List 3 examples of transparent objects:
5. List 3 examples of translucent objects:
6. List 3 examples of opaque objects:
Convex Lenses• Make light rays bend close together towards a central
point (the thickest part)• Magnifies the object to make it look larger than the
original object It might also make the image appear to be upside down, this happens when the light rays cross.
Day 6
More convex lenses
• They are thicker in the middle than the edges
• Light moves into lens, then bends toward thickest part (middle)
Concave lenses• Make the light rays spread out and make objects
look smaller.• They are thinner in the middle than at the edges
and curve inwards.• Light enters and bends toward thickest part (ends)• Used to correct near-sightedness (can’t see far
away)• Help make details look clearer• Not as common as convex lenses, but the two are
often combined to improve the details• The image always stays upright
Concave Lens examples
• Eyeglasses have one convex and one concave surface that work together to bend the light just the right amount before it gets to your eyes
Light: Day 6
1.Convex lenses are thicker in the middle and magnify objects. The rays of light pass through the lens and bend toward the thickest part. Objects appear to be larger.
1.Concave lenses are thicker on the edges than in the middle (curve inward). As light waves enter the lens, they bend toward the thickest part and make objects look smaller and clearer than they are.Concave lenses make the light rays spread out. Objects through a concave lense are always upright.
Sound
• Sound is a form of energy that travels through the air.
• Sound is made when something vibrates
• Vibration is the back and forth movement of matter, which is the beginning of sound
• Click on the sound wave picture to take you to a short video, “What is sound?”
• http://www.nidcd.nih.gov/health/education/video/sound_vid.htm
Day 7
• Vibration causes particles in the air to be pushed quickly (compression). The push stops but it has caused a sound wave that travels to bring the sound to our ears.
Our ears detect the sound wave through the ear’s eardrum and some nerves, then send the signals to our brain. Our brain tells us what sound was just heard. Our brain can quickly identify many different sounds.
Sound Day 1 Notes (day 7)
1.Sound is a form of energy that travels through the air as waves.
2. Sound is vibration you can hear.
3. The loudness ofsound is called volume. The volume of sound is measured in units called decibels.
Sound- energy that travels through matter in waves in high and low pressure.
Vibration- A quick back and forth movement of matter
waves
Click on link215-41_l.mov
Sound waves are the way sound travels. Sound travels in compression waves, similar to the slinky activity.
click here
Day 8
Different Waves
• Click here to see demonstrations of sound waves
Sound Notes – Day 21. Sound travels through the air as compression waves.
2. Sound has to travel through a medium.
3. Sound travels fastest through steel. Sound travels slowest through air.
4. What form of matter is left? Air
Vibrations move by traveling from place to place. In air, the sound moves between the air particles, the particles vibrate where they are. This is why you can still hear sounds even though the wind is not blowing.
5.Amplitude is the measure of the amount of energy in a sound wave.
Sound Waves – Compression wave that carries energy through matter
Loudness – Amount of sound energy
Amplitude – this is the measure of the amount of energy in a sound wave, the more energy the
higher the volume (loudness of a sound)
• What is too loud?
Click on me to find out…
How does sound change?
Test your range…
How High can you sing?????
How Low can you sing?????
Brainpop-sound video
How does sound travel?
• Sound travels through any type of matter.• The matter that carries the sound wave is
called a medium.• The speed of sound depends on the
medium through which it is moving.• It does not depend on how loud or soft,
how high or low.• Sound also moves faster in warm air,
solids and liquids and is slower in cold air and gases.
ECHO
• An echo happens when sound bounces off a surface
• You can get an idea of the speed of sound if you live near a cliff, mountain, or large building that makes a good echo. The delay between the original noise (a clap for example) and its echo is the time it has taken the sound to travel there and back.
What is pitch?
• Pitch is a measure of how high or low a sound is’
• Pitch depends on how fast the source of the sound is vibrating, this is called frequency
• Sounds with a high pitch have a high frequency
• Sounds with a low pitch have a low frequency
String instruments
• Which instrument will have a higher sound? Why?
• What will happen if you loosen one of the strings on you cello?
Drums• Which drum will have the highest sound?
Are Pitch and Loudness different?? Why or Why not?
Why are some sounds louder than others???
Do You Know???
1.Wavelength is the distance between two compressions (points) of a sound wave.
2. Frequency is measured as the number of vibrations per second. It determines the pitch of a sound.
3. Pitch is a measure of how high or low a sound is. It depends on how fast the source of a sound is vibrating and changes based on the nature and length of the vibrating object.
High frequency (small space between waves) = high pitch.
Low frequency (long space between waves)= low pitch
4. Amplitude is a measure of the amount of energy in a sound wave. It can be seen in the height of a sound wave and it determines volume.
High amplitude (tall waves) = loud volume
Low amplitude (short waves) = soft volume.
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