| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 2.93 |
| Score | 0% | 59% |
Changes to an object's speed or direction of motion are caused by which of the following?
a force |
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power |
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kinetic energy |
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work |
Force is applied to change an object's speed or direction of motion.
Scalar quantities are fully described by which of the following?
a magnitude and a polarity |
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a magnitude only |
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a magnitude and a direction |
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a direction only |
Velocity and displacement are vector quantities which means each is fully described by both a magnitude and a direction. In contrast, scalar quantities are quantities that are fully described by a magnitude only. A variable indicating a vector quantity will often be shown with an arrow symbol: \(\vec{v}\)
The crust and upper mantle of the earth is called the:
atmosphere |
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geosphere |
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lithosphere |
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hydrosphere |
The biosphere is the global ecological system integrating all living beings and their relationships. This includes their interactions with the lithosphere (the rigid outer part of the earth, consisting of the crust and upper mantle), hydrosphere (all surface water), and atmosphere (the envelope of gases surrounding the planet).
Acceleration is the rate of change of velocity per unit of time. Which of these is the formula for acceleration?
\(\vec{a} = { \Delta \vec{v} \over t }\) |
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\(\vec{a} = \Delta \vec{v} t \) |
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\(\vec{a} = { t \over \Delta \vec{v} }\) |
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\(\vec{a} = { \vec{v} \over t }\) |
Acceleration is the rate of change of velocity per unit of time. In physics, the delta symbol (\(\Delta\)) represents change so the formula for acceleration becomes \(\vec{a} = { \Delta \vec{v} \over t }\)
During digestion, after proteins are broken down where does the undigested food go next?
small intestine |
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esophagus |
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stomach |
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large intestine |
Food is mixed with gastric acid and pepsin in the stomach to help break down protein.