| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.39 |
| Score | 0% | 68% |
Which of the following is the formula for power?
\(P = w t\) |
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\(P = {\vec{w} \over t}\) |
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\(P = \vec{w}t\) |
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\(P = {w \over t}\) |
Power is the rate at which work is performed or work per unit time: \(P = {w \over t}\) and is measured in watts (W).
The hottest of Earth's atmospheric layers is which of the following?
troposphere |
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mesosphere |
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thermosphere |
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stratosphere |
Temperatures again increase with altitude in the thermosphere which is the hottest (4,530 °F / 2,500 °C) atmospheric layer due to direct exposure to the Sun's radiation. However, the gas in this layer is highly diluted so even though the atoms of gas may be very high in temperature, there are too few of them to effectively transfer much heat.
Meteoroids, meteors and meteorites are categorized based on which of the following?
their temperature |
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their density |
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their size |
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their location |
Smaller rocks shed by asteroids and comets are called meteoroids. When these rocks reach Earth's atmosphere, they burn up in the mesosphere and become meteors. If a meteor manages to reach the Earth, it is called a meteorite.
The number system most used in science is the:
American system |
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British system |
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English system |
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metric system |
The metric system is a number system that designates one base unit for each type of measurement. For example, the base unit for length is the meter and the base unit for mass is the gram.
What part of the brain is responsible for for balance, movement, and muscle coordination?
cerebellum |
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brainstem |
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cerebrum |
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medulla |
The cerebellum is a large cluster of nerves at the base of the brain that's responsible for balance, movement, and muscle coordination.