| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 2.83 |
| Score | 0% | 57% |
The angle of reflection is equal to which the following?
angle of incidence |
|
refractive index |
|
90° |
|
focal point |
The law of reflection specifies how waves, including light waves, bounce off of surfaces. Specifically, the angle of incidence of the approaching wave is equal to the angle of reflection of the reflected wave as measured from a line perpendicular (90°) to the surface.
Which of the following describes the Earth's outer core?
makes up most of the Earth's volume |
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primarily solid |
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solid |
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liquid |
The Earth's core is divided into the liquid outer core (1,430 miles or 2,300 km radius) and the solid inner core (745 miles or 1,200 km radius).
The Sun is a __________-type main-sequence star.
E |
|
G |
|
S |
|
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.
Which of the following is not true of light waves?
travel faster than sound waves |
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are mechanical waves |
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can travel through a vacuum |
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are electromagnetic waves |
Unlike mechanical sound waves that require a physical medium for propagation, light waves are electromagnetic and can travel through empty space. Light waves are also much faster, travelling at 186,000 m/s vs. 343 m/s for sound waves.
Scavengers break down the dead bodies of plants and animals into which of the following?
producers |
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simple nutrients |
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complex carbohydrates |
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carrion |
Like decomposers, scavengers also break down the dead bodies of plants and animals into simple nutrients. The difference is that scavengers operate on much larger refuse and dead animals (carrion). Decomposers then consume the much smaller particles left over by the scavengers.