| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.20 |
| Score | 0% | 64% |
Momentum is a measure of how difficult it is for a moving object to stop. Which of the following is the formula for momentum?
\(\vec{p} = m\vec{v}\) |
|
\(\vec{p} = { \vec{v} \over m}\) |
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none of these |
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\(\vec{p} = {m \over \vec{v}}\) |
Momentum is a measure of how difficult it is for a moving object to stop and is calculated by multiplying the object's mass by its velocity: \(\vec{p} = m\vec{v}\). Like velocity, momentum is a vector quantity as it expresses force applied in a specific direction.
What part of the nervous system controls simple reflexes?
spinal cord |
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autonomic |
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cerebrum |
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medulla |
The spinal cord connects the brain to the body's network of nerves. It carries impulses between all organs and the brain and controls simple reflexes.
50°F is how many °C?
58 |
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-10 |
|
122 |
|
10 |
The formula to convert from F° to C° is:
\(C° = {5 \over 9} (F° - 32)\)
plugging in our values gives:
\(C° = {5 \over 9} (50 - 32)\)
\(C° = {5 \over 9} (18)\)
\(C° = {90 \over 9}\)
\(C° = 10\)
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 much slower than a light wave |
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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 |
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.
The Earth's rocks fall into three categories based on how they're formed. Which of the following is formed from the hardening of molten rock?
sedimentary |
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igneous |
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metamorphic |
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marble |
The Earth's rocks fall into three categories based on how they're formed. Igneous rock (granite, basalt, obsidian) is formed from the hardening of molten rock (lava), sedimentary rock (shale, sandstone, coal) is formed by the gradual despositing and cementing of rock and other debris, and metamorphic rock (marble, slate, quartzite) which is formed when existing rock is altered though pressure, temperature, or chemical processes.