| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.45 |
| Score | 0% | 69% |
Changes to an object's speed or direction of motion are caused by which of the following?
kinetic energy |
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a force |
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power |
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work |
Force is applied to change an object's speed or direction of motion.
As part of digestion, the liver produces bile which breaks down:
protein |
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starches |
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fat |
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sugars |
The liver produces bile which emulsifies (separates) fat.
As a cold front moves into an area, the heavier cool air __________ the lighter warm air that it is replacing.
pushes under |
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cancels out |
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pushes above |
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mixes with |
A cold front is a warm-cold air boundary with the colder air replacing the warmer. As a cold front moves into an area, the heavier cool air pushes under the lighter warm air that it is replacing. The warm air becomes cooler as it rises and, if the rising air is humid enough, the water vapor it contains will condense into clouds and precipitation may fall.
The gravitational interaction of Earth and the Moon is responsible for which of these?
day and night cycle |
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tides |
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seasons |
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the northern lights |
Tides are caused by the gravitational interaction of Earth and the Moon.
Velocity is the rate at which an object changes position. What is the formula for velocity?
none of these |
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\(\vec{v} = { t \over \vec{d} } \) |
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\(\vec{v} = \vec{d}t \) |
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\(\vec{v} = { \vec{d} \over t } \) |
Velocity is the rate at which an object changes position. Rate is measured in time and position is measured in displacement so the formula for velocity becomes \(\vec{v} = { \vec{d} \over t } \)