| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.20 |
| Score | 0% | 64% |
When two air masses meet and neither is displaced, what kind of front is present?
cold |
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warm |
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stationary |
|
occluded |
When two air masses meet and neither is displaced, a stationary front is created. Stationary fronts often cause persistent cloudy wet weather.
Which of the following does not represent the freezing point of water?
32°F |
|
0°C |
|
0°F |
|
273K |
The Fahrenheit scale fixes the freezing point of water at 32°F, the Celsuis scale at 0°C, and the Kelvin scale at 273K.
50°F is how many °C?
-10 |
|
10 |
|
122 |
|
58 |
The formula to convert from F° to C° is:
\(C° = {5 \over 9} (F° - 32)\)
plugging in our values gives:
\(C° = {5 \over 9} (50 - 32)\)
\(C° = {5 \over 9} (18)\)
\(C° = {90 \over 9}\)
\(C° = 10\)
The pitch of the siren of an approaching ambulance changes as it approaches you. This is an example of which of the following?
reflection |
|
sound radiation |
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Doppler effect |
|
refraction |
The Doppler effect occurs when the source or listener (or both) of sound waves is moving. If they're moving closer together, the listener perceives the sound with a higher pitch and, when they're moving apart, the listener perceives the sound with a lower pitch.
Which of the following is not true about mass and weight?
weight depends on the location where it is measured |
|
weight is the force exerted on an object by gravity |
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mass depends on the location where it is measured |
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mass is the amount of matter something has |
Mass is the amount of matter something has while weight is the force exerted on an object's mass by gravity. So, although a person's mass doesn't change when going from the Earth to the Moon, their weight will decrease because the force of the Moon's gravity is much less than that of Earth.