# True or False

1. Nov 28, 2003

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DO NOT GIVE ME THE ANSWERS, JUST TELL ME HOW MANY ARE WRONG AND I WILL RESEARCH ALL THE ANSWERS.

F. Simple harmonic motion can be represented by a sine curve
T. A violin string which vibrates with a frequency of 196 Hz produces a sound wave with a a frequency of 1/196 Hz
F. A pendulum with a mass of 10 g and a length of 20 cm swings back and forth more frequently than a pendulum with a mass of 20 g and a length of 10 cm
F. The wavelength produced by a violin string with a frequency of 196 Hz is greater than the wavelength produced by a piano string with a frequency of 262 Hz.
T. When a tranverse wave moves in a medium, the motion of the medium, the motion of the medium is in the same direction as the motion of the wave
F.When the crest of two waves overlap the result is destructive interference
T. All elastic materials have a natural frequency
T. Accelerating electric charges produce longitudinal waves.
T. In a vacuum, blue light moves at a faster speed than red light.
T. Blue light has a higher frequency than red light

2. Nov 28, 2003

### chroot

Staff Emeritus
Seven are wrong.

- Warren

3. Nov 28, 2003

### Security

NOOOOOOO!!!!!!

4. Nov 28, 2003

### chroot

Staff Emeritus
Sorry to be the bearer of bad news.

- Warren

5. Nov 28, 2003

### Security

itll come back soon like a couple minutes later with what i suspect are the wrong answers and make them right, k?

6. Nov 28, 2003

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numbers: 1, 2, 3, 4, 7, 8, and 9

7. Nov 28, 2003

### chroot

Staff Emeritus
Almost. 1, 2, 3, 5, 6, 8 and 9 are wrong.

- Warren

8. Nov 28, 2003

### Security

dag i was off my two!!

9. Nov 28, 2003

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Multiple Choice Pt.1

Same as before, just tell me how many wrong answer are their, and ill look back at them. If the "choose as many as apply" questions are wrong, I will give you more of the choices.

Sound waves in air are produced by which of the following? D. a succession of compressions and rarefactions

The seismic waves produced by earthquakes are made up of several kinds of waves, including sound waves. What happens to the enrgy contained in the sound waves? (choose as many as apply) A. 'It makes rocks vibrate in the same direction as the waves' and D.'Because solids are generally more elastic than gases, the energy is transmitted more quickly through the earth than it would be if the sound waves traveled through air.

As a train approaches a grade crossing, it sounds its whistle, whose frequency is 350 Hz. What is the frequency of the sound heard by someone waiting at the grade crossing? B. Greater than 350 Hz

The pattern produced in the illustration on page 91 of this study guide most likely results from E. polarization of light waves

Shock waves are produced by which of the following? (choose as many as apply) C. 'by supersonic aircraft' and E. "only at the moment an aircraft breaks the 'sound barrier'"

Which of the following is true of a solar eclipse? (choose as many as apply) A. It is caused by the sun's shadow on the earth and E. Each solar eclipse can only be obeserved in small region of the earth at any given time, whereas lunar eclipses can be observed by anyone on the nighttime half of the earth

In what ways are sound and light waves similar? (choose as many as apply) B They both behave as both particles and waves and A. They both are forms of energy.

10. Nov 28, 2003

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Another question i forgot to post:

How does a wave differ from a vibration? BA wave travels in spacem but a vibration does not.

11. Nov 30, 2003

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can any help out?

12. Dec 1, 2003

### chroot

Staff Emeritus
Waves move (propagate) -- vibrations stay in one place.

- Warren

13. Dec 1, 2003

### Security

so i was right? also, how many questions are wrong in that mc column

14. Dec 1, 2003

### chroot

Staff Emeritus
Re: Multiple Choice Pt.1

Correct.
Correct.
Correct.
Obviously, I can't help you with this. I don't have the illustration on page 91.
E does not apply. The shock wave is present the entire time the aircraft is supersonic. There may be other choices that also apply, but you did not provide them to me, so I do not know.
A is incorrect. The sun does not have a shadow -- it's a light source. The moon does. Once again, there may be other correct choices, but you did not provide them to me, so I do not know.
B is incorrect -- sound waves do not behave like particles. A is also very questionable -- a physicist would not say either is "a form of energy." It is true, however, that both sound and light waves transmit energy.

- Warren

15. Dec 1, 2003

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Multiple Choices Pt2

In what ways are sound and light waves different? (Choose as many as apply) A.The speed of light waves is greater than the speed of sound waves and E. Sound waves experience the Doppler effect, while light waves do not.

Which of the following statements is true of ultraviolet light? (choose as many as apply) C. The earth's atmosphere is completely opaque to it. and D. It is responsible for sunburns.

When blue light strikes a window pane which is completely transparent to visble light, what happens? E. The blue light is transmitted through the glass.

When blue light strikes an opaque object whose resonant frequency is the same as the frequency of blue light, what happens? A. The amplitude of the vibrations of the electrons in the object

When blue light strikes an opaque object whose resonant frequency is lower than the frequency of blue light, what happens? B. The object becomes warm

If white light falls on a pigment that absorbs magenta light, what color will the reflected light appear? D. green

What color does a magenta pigment absorb? B. green

16. Dec 1, 2003

### chroot

Staff Emeritus
E is not correct. There may be other answers that are correct, but you did not provide them to me, so I do not know.
C is not correct. If it were, you would not get a sunburn at all.
This is false. Most of the light will be transmitted, but some small amount will be reflected. The amount that is reflected depends upon the angle of incidence, the thickness of the glass, and the frequency of the light.
I assume you mean 'increases.' If so, this is correct.
"Becomes warm" means the same thing as "vibrates more rapidly." So this is not correct. If the light does not meet the material's "resonant frequency" (this is a bad way to describe this, by the way) then it will pass right through.
Do cyan and yellow make green? I guess so.
A magenta pigment absorbs both yellow and cyan, I'd assume. I'm not sure if you can call this green or not -- but I assume you can.

- Warren

17. Dec 1, 2003

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Pt1 followup: other choices

Pt1 other choices:

2. (B) It makes rocks vibrate at right angles to the waves. (C) Because solids generally have higher densities than gases, the energy is transmitted more quickly through the earth than it would be if the sound waves traveled through air.

5. (B) when the crests of some sound waves overlap the troughs of others, resulting in destructive interference. (A) when the crests of sound waves overlap, causing constructive interference (D)by subsonic aircraft.

7. (B) It is caused by the moon's shadow on the earth. (C) It is caused by the earth's shadow on the sun. (D) It occurs more often than a lunar eclipse.

8. (C) They both can experience interference. (D) They both move in 3-dimensional space. (E) They both are transverse and therefore both can be polarized.

18. Dec 1, 2003

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Pt2 other choices

1 - - (B) Sound waves can travel in a vacuum, but light waves cannot. (C) Sound waves are longitudinal, while light waves are transverse. (D) Light waves are produced by accelerating electric charges, while sound waves are produced by the mechanical vibration of matter.

2 - - (A) It has a higher frequency than that of visible light (B) Unlike visible light, it is not an electromagnetic wave

3 - - (A) The amplitude of the vibrations of the electrons in the glass become larger. (B) The glass becomes warm. (C) The blue light is absorbed without reemission. (D) The blue light is reflected by the glass

4 - - It says its larger, not increases/ (B)The object beomces warm. (C)The blue light is absorbed without reemission. (D)The blue light is reflected by the electrons in the object. (E) The blue light is transmitted through the object.

5 - - (A) The amplitude of the vibrations of the electrons in the object become larger. (C) The blue light is absorbed without reemission (D) The blue light is reflected by the electrons in the object. (E) The blue light is transmitted through the object