| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.16 |
| Score | 0% | 63% |
-40°F is how many °C?
\({40 \over 9}\) |
|
\(-{40 \over 9}\) |
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-8 |
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-40 |
The formula to convert from F° to C° is:
\(C° = {5 \over 9} (F° - 32)\)
plugging in our values gives:
\(C° = {5 \over 9} (-40 - 32)\)
\(C° = {5 \over 9} (-72) = {{-72 \times 5} \over 9}\)
\(C° = {-360 \over 9}\)
\(C° = -40\)
The pitch of the siren of an approaching ambulance changes as it approaches you. This is an example of which of the following?
reflection |
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refraction |
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sound radiation |
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Doppler effect |
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.
All surface water is part of the:
hydrosphere |
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lithosphere |
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geosphere |
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atmosphere |
The biosphere is the global ecological system integrating all living beings and their relationships. This includes their interactions with the lithosphere (the rigid outer part of the earth, consisting of the crust and upper mantle), hydrosphere (all surface water), and atmosphere (the envelope of gases surrounding the planet).
Which of the following is the smallest component of an element that still retains the properties of the element?
molecule |
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atom |
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neutron |
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element |
An atom is the smallest component of an element that still retains the properties of the element.
Which of the following is not true about mass and weight?
weight is the force exerted on an object by gravity |
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weight depends on the location where it is measured |
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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.