| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.64 |
| Score | 0% | 73% |
A major difference between sound waves and light waves is which of the following?
a sound wave is mechanical while a light wave is electromagnetic |
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a sound wave is much slower than a light wave |
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a sound wave cannot travel through a vacuum |
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all of these are correct |
A vibrating object produces a sound wave that travels outwardly from the object through a medium (any liquid or solid matter). The vibration disturbs the particles in the surrounding medium, those particles disturb the particules next to them, and so on, as the sound propagates away from the vibration.
Water has a refractive index of 1.33. Which of the following is true?
light travels 1.33 times faster in a vacuum than it does in water |
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light is 1.33 times brighter in a vacuum than it is in water |
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light travels 1.33 times slower in a vacuum than it does in water |
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light is 1.33 times dimmer in a vacuum than it is in water |
The speed of light varies based on the material that the waves are passing through. The refractive index of a material indicates how easily light travels through it compared to how easily light travels through a vacuum. For example, the refractive index of water is 1.33, meaning that light travels 1.33 times faster in a vacuum than it does in water.
pH is a scale that measures of how basic or acidic a solution is. A solution with a pH of 9 is:
alkaline |
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neutral |
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acidic |
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water |
An acid is a substance that gives up positively charged hydrogen ions (H+) when dissolved in water. A base (alkaline) gives up negatively charged hydroxide ions (OH-) when dissolved in water. pH is a scale that measures of how basic or acidic a solution is. Numbered from 0 to 14, solutions with a pH of 7 are neutral, less than 7 are acidic, more than 7 are alkaline.
Herbivores are __________ that subsist on producers like plants and fungus.
primary consumers |
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secondary consumers |
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scavengers |
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tertiary consumers |
Primary consumers (herbivores) subsist on producers like plants and fungus. Examples are grasshoppers, cows, and plankton.
An endoskeleton (internal skeleton) is a charateristic of __________ animals, including humans.
sentient |
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vertebrate |
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arthropod |
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spiny |
An endoskeleton (internal skeleton) is a charateristic of vertebrate animals, including humans.