| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 2.91 |
| Score | 0% | 58% |
Which of the following is not a characteristic of the Sun?
makes up over 99% of the mass of the solar system |
|
is a yellow dwarf star |
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formed 2.6 billion years ago |
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is composed of hydrogen and helium |
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.
-40°F is how many °C?
\({40 \over 9}\) |
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\(-{40 \over 9}\) |
|
-8 |
|
-40 |
The formula to convert from F° to C° is:
\(C° = {5 \over 9} (F° - 32)\)
plugging in our values gives:
\(C° = {5 \over 9} (-40 - 32)\)
\(C° = {5 \over 9} (-72) = {{-72 \times 5} \over 9}\)
\(C° = {-360 \over 9}\)
\(C° = -40\)
During digestion, the kidneys filter substances from the blood. Which of the following is not filtered by the kidneys?
minerals |
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fats |
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water |
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salt |
Chemical waste like excess water, minerals, and salt are filtered from the blood by the kidneys and secreted into the urine. Urine is transported from the kidneys to the bladder through ureters.
A major difference between sound waves and light waves is which of the following?
all of these are correct |
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a sound wave is mechanical while a light wave is electromagnetic |
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a sound wave cannot travel through a vacuum |
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a sound wave is much slower than a light wave |
A vibrating object produces a sound wave that travels outwardly from the object through a medium (any liquid or solid matter). The vibration disturbs the particles in the surrounding medium, those particles disturb the particules next to them, and so on, as the sound propagates away from the vibration.
Convert -20C° to F°.
-36 |
|
78 |
|
36 |
|
-4 |
To convert from C° to F° use:
\(F° = {9 \over 5}C° + 32\)
\(F° = {9 \over 5}(-20) + 32\)
\(F° = {-180 \over 5} + 32\)
\(F° = -36 + 32 = -4\)