| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.01 |
| Score | 0% | 60% |
Which of the following is not a medium for sound waves?
liquid |
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solid |
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none of these is a medium for sound waves |
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vacuum |
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.
The heat from the Sun traveling to Earth is an example of which of the following?
convection |
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conduction |
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radiation |
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electricity |
Radiation occurs when electromagnetic waves transmit heat. An example is the heat from the Sun as it travels to Earth.
The coldest point in the Earth's atmosphere is reached in which atmospheric layer?
mesosphere |
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stratosphere |
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thermosphere |
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troposphere |
In the mesosphere, temperature again drops as altitude increases until the coldest point in the Earth's atmosphere, the mesopause, is reached where temperatures fall to −225 °F (−143 °C).
When the clouds become too saturated with water, the water is released as precipitation in the form of:
ice |
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snow or ice |
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snow |
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rain |
Rising into the atmosphere, the water condenses into clouds. When the clouds become too saturated with water, the water is released as snow or ice precipitation which may warm as it falls to reach Earth as rain.
The __________ is a system of muscles that allows breathing.
pulmonary |
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diaphragm |
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trachea |
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bronchioles |
The diaphragm is a system of muscles that allows breathing. During inhalation, the diaphragm expands and air rushes in to fill the space created. Then, during exhalation, the diaphragm contracts and forces the air back out.