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| order of the eye |
cornea, lens, retina, optic nerve, brain |
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jnc Fri, 12 Mar 2010 02:09:54 GMT |
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| cones |
help you see color |
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jnc Fri, 12 Mar 2010 02:09:54 GMT |
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| rods |
help you see light |
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jnc Fri, 12 Mar 2010 02:08:06 GMT |
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| farsighted |
usually have trouble seeing objects up close
Causes: flatter cornea or shorter eye
the lens focuses the image behind the retina |
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jnc Fri, 12 Mar 2010 02:08:06 GMT |
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| near sightedness |
near sighted eyes can see objects that are close by, but it is hard to see objects far away
Causes: steeper cornea or longer eye
the lens focuses the image in front of the retina |
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jnc Fri, 12 Mar 2010 02:08:06 GMT |
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| Explain why an image appears upside down on your retina and where the image gets turned right side up |
when you see something, the lens focuses an upside down image onto your retina. the retina converts the image to an electrical impulse which is sent up to the brain, via the optic nerve, where the brain turns the image right side up |
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jnc Fri, 12 Mar 2010 02:08:06 GMT |
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| medium |
a substance or material that carries a wave (consists of parts that interact with each other- think of a slinky, each part moves) |
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jnc Fri, 12 Mar 2010 01:40:38 GMT |
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| wave |
a disturbance that travels through air, water, etc. energy is transferred through a wave |
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jnc Fri, 12 Mar 2010 01:40:38 GMT |
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| pitch |
a description of a sound as high or as low, which depends on the frequency of waves |
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jnc Fri, 12 Mar 2010 01:40:38 GMT |
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| interference |
when 2 or more waves arrive at the same place at the same time, they interact in a process called interference |
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jnc Fri, 12 Mar 2010 01:40:38 GMT |
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| frequency |
refers to how often an event occurs. for waves, it refers to the number of cycles that pass an observer in a given amount of time. it is measured in hertz (#or cycles per second) |
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jnc Fri, 12 Mar 2010 01:36:15 GMT |
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| amplitude |
the length from the resting point to a crest OR the resting point to the trough (the larger the amplitude, the higher the intensity) |
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jnc Fri, 12 Mar 2010 01:36:15 GMT |
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| diffraction |
bending of waves around the edge of an object |
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jnc Fri, 12 Mar 2010 01:36:15 GMT |
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| reflection |
the bouncing back of a wave after it strikes a boundary that does not absorb all of the wave's energy |
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jnc Fri, 12 Mar 2010 01:36:15 GMT |
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| refraction |
change of direction or bending of waves (occurs because waves move at different speeds in the different mediums) |
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jnc Fri, 12 Mar 2010 01:30:32 GMT |
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| Why does the pupil change sizes when the light changes? |
the pupil is the hole in the iris. The amount of light needed is controlled by the iris. When it is very bright, the pupil gets smaller. When it is dark, the pupil enlarges to get as much light as possible to be able to see |
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jnc Fri, 12 Mar 2010 01:30:32 GMT |
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| explain the difference between constructive and destructive interference |
Constructive-when multiple waves combine together to create an even bigger wave (crests line up)
Destructive-when multiple waves combine together to disrupt the original wave causing an even smaller wave or mo wave at all (Crests DON'T line up) |
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jnc Fri, 12 Mar 2010 01:30:32 GMT |
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| during the musical straw activity, why did the shorter straw have a higher pitch? |
the tips vibrate at a specific wavelength and frequency based on the length of the straw. If you change the length of the straw, you are changing the wavelength and frequency which changer the pitch |
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jnc Fri, 12 Mar 2010 01:30:32 GMT |
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| Who uses sonar and why? |
-commercial fishing
-cameras to focus
-cars to warn nearby objects
-ultrasonic waves used to clean jewelry, electronic components, and delicate machine parts
-ultrasonic waves used to diagnose medical problems:similar to sonar, can treat medical conditions by destroying unwanted tissue |
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jnc Fri, 12 Mar 2010 00:56:52 GMT |
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| compression |
the part of the wave that is pushed or compressed together |
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jnc Fri, 12 Mar 2010 00:56:52 GMT |
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| rarefaction |
the part of the wave that is spread out |
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jnc Fri, 12 Mar 2010 00:56:52 GMT |
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| What does sound travel slowest through? |
gases |
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jnc Fri, 12 Mar 2010 00:56:52 GMT |
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| What does sound travel fastest through? |
solids |
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jnc Fri, 12 Mar 2010 00:50:53 GMT |
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| give an example of something that has a frequency that is too low for humans to hear |
a hand that is flapping |
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jnc Fri, 12 Mar 2010 00:50:53 GMT |
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| give an example of something that has a frequency too high for humans to hear at |
dog whistle |
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jnc Fri, 12 Mar 2010 00:50:53 GMT |
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| what frequency range do humans hear at? |
20-20,000 Hertz |
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jnc Fri, 12 Mar 2010 00:50:53 GMT |
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| cochlea |
the vibrations move to the snail-shaped cochlea. it has hundreds of nerve fibers which convert the sound into an electrical impulse that is sent to the brain |
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jnc Fri, 12 Mar 2010 00:47:00 GMT |
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| Hammer, anvil, stirrup |
the vibrations hit the middle ear, which consists of three small bones. the hammer, anvil, and stirrup send the vibrations along into the inner ear |
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jnc Fri, 12 Mar 2010 00:47:00 GMT |
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| Ear drum |
the waves hit a lightly stretched membrane called the eardrum. the eardrum vibrates |
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jnc Fri, 12 Mar 2010 00:47:00 GMT |
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| Ear Canal |
the waves move through the ear canal |
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jnc Fri, 12 Mar 2010 00:47:00 GMT |
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| Outer ear |
Sound waves enter the outer ear which acts as a funnel |
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jnc Fri, 12 Mar 2010 00:42:22 GMT |
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| What is an example of a situation where you might encounter the Doppler Effect? |
when a car passes you on the road-the waves are compresses as it moves towards you. they spread out as it moves past you |
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jnc Fri, 12 Mar 2010 00:42:22 GMT |
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| what is the Doppler Effect? |
change in sound or light that occurs whenever there is motion between the source and its observer |
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jnc Fri, 12 Mar 2010 00:42:22 GMT |
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| Explain how sound is created? |
vibrations occur-sound is produced when matter vibrates |
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jnc Fri, 12 Mar 2010 00:42:22 GMT |
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