| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.65 |
| Score | 0% | 73% |
Scalar quantities are fully described by which of the following?
a magnitude and a polarity |
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a magnitude and a direction |
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a direction only |
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a magnitude 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 Sun is a __________-type main-sequence star.
S |
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E |
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G |
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D |
The Sun is a G-type main-sequence star (G2V) but is informally known as a yellow dwarf star. Composed of 73% hydrogen and 25% helium, the hot plasma that makes up the Sun reaches 9,900°F (5,505°C) at the surface. It formed approximately 4.6 billion years ago and makes up 99.86% of the mass in the solar system.
In the food chain, bacteria and fungi convert the organic matter in the dead bodies of plants and animals into simple nutrients. Bacteria and fungi are:
scavengers |
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producers |
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primary consumers |
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decomposers |
Decomposers (saprotrophs) are organisms such as bacteria and fungi that break down the organic matter in the dead bodies of plants and animals into simple nutrients.
Secondary consumers that also eat producers are known as:
herbivores |
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carnivores |
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omnivores |
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scavengers |
Secondary consumers (carnivores) subsist mainly on primary consumers. Omnivores are secondary consumers that also eat producers. Examples are rats, fish, and chickens.
Carbohydrates are found in:
sugars and starches |
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animal sources |
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food additives |
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vegetable oils |
Carbohydrates are major sources of energy for the body and are found in sugars (fruit, cane sugar, beets) and starches (bread, rice, potatoes, pasta).