| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.24 |
| Score | 0% | 65% |
Water coming to a boil on a stove, ice melting, and steam from a cup of coffee are all examples of which of the following?
conduction |
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radiation |
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convection |
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reflection |
Convection is the transfer of heat by the circulation or movement of the heated parts of a liquid or gas.
The hottest of Earth's atmospheric layers is which of the following?
stratosphere |
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mesosphere |
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troposphere |
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thermosphere |
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.
Which of the following is the correct order for types of radiation from lowest to highest frequency?
radio waves → visible light → gamma rays |
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microwaves → radio waves → visible light |
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visible light → ultraviolet light → radio waves |
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infrared waves → microwaves → ultraviolet light |
The electromagnetic spectrum covers all possible wavelengths and frequencies of radiation. From lowest frequency (longest wavelength) to highest frequency (shortest wavelength) radiation: radio waves → microwaves → infrared waves → visible light → ultraviolet light → X-rays → gamma rays.
Momentum is a measure of how difficult it is for a moving object to stop. Which of the following is the formula for momentum?
\(\vec{p} = m\vec{v}\) |
|
\(\vec{p} = {m \over \vec{v}}\) |
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none of these |
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\(\vec{p} = { \vec{v} \over m}\) |
Momentum is a measure of how difficult it is for a moving object to stop and is calculated by multiplying the object's mass by its velocity: \(\vec{p} = m\vec{v}\). Like velocity, momentum is a vector quantity as it expresses force applied in a specific direction.
Blood pressure is generally highest in which of the following?
arteries |
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capillaries |
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veins |
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heart |
Arteries are thick-walled because they carry oxygenated blood at high pressure, veins are comparatively thin-walled as they carry low-pressure deoxygenated blood.