| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.51 |
| Score | 0% | 70% |
As a cold front moves into an area, the heavier cool air __________ the lighter warm air that it is replacing.
pushes under |
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cancels out |
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mixes with |
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pushes above |
A cold front is a warm-cold air boundary with the colder air replacing the warmer. As a cold front moves into an area, the heavier cool air pushes under the lighter warm air that it is replacing. The warm air becomes cooler as it rises and, if the rising air is humid enough, the water vapor it contains will condense into clouds and precipitation may fall.
Which of the following is sedimentary rock?
basalt |
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sandstone |
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obsidian |
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slate |
The Earth's rocks fall into three categories based on how they're formed. Igneous rock (granite, basalt, obsidian) is formed from the hardening of molten rock (lava), sedimentary rock (shale, sandstone, coal) is formed by the gradual despositing and cementing of rock and other debris, and metamorphic rock (marble, slate, quartzite) which is formed when existing rock is altered though pressure, temperature, or chemical processes.
A major difference between sound waves and light waves is which of the following?
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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a sound wave is mechanical while a light wave is electromagnetic |
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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.
212°F is how many °C?
0 |
|
-100 |
|
100 |
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\(135 {5 \over 9}\) |
The formula to convert from F° to C° is:
\(C° = {5 \over 9} (F° - 32)\)
plugging in our values gives:
\(C° = {5 \over 9} (212 - 32)\)
\(C° = {5 \over 9} (180) = {{180 \times 5} \over 9}\)
\(C° = {900 \over 9}\)
\(C° = 100\)
"The acceleration of an object as produced by a net force is directly proportional to the magnitude of the net force, in the same direction as the net force, and inversely proportional to the mass of the object." This describes which of Newton's laws of motion?
third |
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first |
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second |
|
fourth |
Newton's second law of motion states that The acceleration of an object as produced by a net force is directly proportional to the magnitude of the net force, in the same direction as the net force, and inversely proportional to the mass of the object. This law basically means that the greater the mass of an object, the more force is needed to overcome its inertia.