| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.26 |
| Score | 0% | 65% |
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.
What is the body's largest artery?
aorta |
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capillary |
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vena cava |
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arteriole |
The aorta is the body's largest artery and receives blood from the pulmonary vein via the left ventricle. From there, blood is circulated through the rest of the body through smaller arteries called arterioles that branch out from the heart. Finally, blood is delivered to bodily tissues through capillaries.
Which of the following describes the Earth's mantle?
primarily solid |
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primarily liquid |
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solid |
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liquid |
Mantle makes up 84% of the Earth's volume and has an average thickness of approximately 1,800 miles (2,900 km). It is dense, hot, and primarily solid although in places it behaves more like a viscous fluid as the plates of the upper mantle and crust gradually "float" along its circumference.
Scavengers break down the dead bodies of plants and animals into which of the following?
simple nutrients |
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producers |
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carrion |
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complex carbohydrates |
Like decomposers, scavengers also break down the dead bodies of plants and animals into simple nutrients. The difference is that scavengers operate on much larger refuse and dead animals (carrion). Decomposers then consume the much smaller particles left over by the scavengers.
What part of the nervous system is responsible for controlling involuntary actions like breathing, swallowing, and heartbeat?
medulla |
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cerebrum |
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spinal cord |
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cerebellum |
Part of the brainstem, the medulla is the connection between the brain and the spinal cord. It controls involuntary actions like breathing, swallowing, and heartbeat.