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CBSE Class 9 Answered

why do you see rainbow colour patterns on a CD?
Asked by ashwati | 05 Sep, 2008, 10:09: PM
answered-by-expert Expert Answer

Like water drops in falling rain, the CD separates white light into all the colors that make it up. The colors you see reflecting from a CD are interference colors, like the shifting colors you see on a soap bubble or an oil slick. You can think of light as as being made up of waves-like the waves in the ocean. When light waves reflect off the ridges on your CD, they overlap and interfere with each other. Sometimes the waves add together, making certain colors brighter, and sometimes they cancel each other, taking certain colors away

Answered by | 06 Sep, 2008, 07:50: AM

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CBSE 9 - Physics
An object of mass 1kg is falling from the height h=10m.calculate a) the total energy of an object at h=10m b) potential energy of the object when it is at h=4m c) kinetic energy of the object when it is at h=4m d) what will be the speed of the object when it hits the ground
Asked by mailtoparvathyprajith | 08 Feb, 2024, 06:45: PM
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CBSE 9 - Physics
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Asked by mailtoparvathyprajith | 08 Feb, 2024, 12:32: PM
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CBSE 9 - Physics
Why do we feel light on our feet when standing in a swimming pool with water up to our armpits ?
Asked by mailtoparvathyprajith | 08 Feb, 2024, 12:13: PM
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CBSE 9 - Physics
The average speed of a moving body can never be zero but the average velocity of a moving body can be zero. Justify.
Asked by mailtoparvathyprajith | 06 Feb, 2024, 09:50: PM
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CBSE 9 - Physics
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Asked by mailtoparvathyprajith | 06 Feb, 2024, 09:10: PM
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CBSE 9 - Physics
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Asked by mailtoparvathyprajith | 06 Feb, 2024, 09:00: PM
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CBSE 9 - Physics
when an arrow is shot from its bow it has kinetic Energy. From where does it get the kinetic Energy
Asked by mailtoparvathyprajith | 06 Feb, 2024, 08:44: PM
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CBSE 9 - Physics
If person A reaches the 2nd floor Of a shopping mall by lift and Person B reaches the same floor by stairs and both their masses are same. Is work done by person B is greater than Person A  against gravitational force.Justify your answer
Asked by mailtoparvathyprajith | 06 Feb, 2024, 08:24: PM
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CBSE 9 - Physics
calculate the amount of work required to stop a car of 1000kg moving with speed of 72km/h
Asked by sadhanaasadhanaa67 | 04 Feb, 2024, 12:27: PM
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CBSE 9 - Physics
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Asked by mailtoparvathyprajith | 31 Jan, 2024, 06:55: PM
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