| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.41 |
| Score | 0% | 68% |
Momentum is a measure of how difficult it is for a moving object to stop. Which of the following is the formula for momentum?
\(\vec{p} = { \vec{v} \over m}\) |
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\(\vec{p} = m\vec{v}\) |
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\(\vec{p} = {m \over \vec{v}}\) |
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none of these |
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.
A major difference between sound waves and light waves is which of the following?
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 |
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all of these are correct |
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.
Changes to an object's speed or direction of motion are caused by which of the following?
work |
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a force |
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power |
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kinetic energy |
Force is applied to change an object's speed or direction of motion.
A large naturally occurring community of flora and fauna occupying a major habitat is:
a population |
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a food chain |
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a community |
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a biome |
A biome is a large naturally occurring community of flora (plants) and fauna (animals) occupying a major habitat (home or environment).
Which of Earth's layers has weather?
stratosphere |
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troposphere |
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thermosphere |
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mesosphere |
The Earth's atmosphere has several layers starting with the troposphere which is closest in proximity to the surface. Containing most of the Earth's breathable air (oxygen and nitrogen), it's a region with warmer temperatures closer to the surface and cooler temperatures farther away which results in the rising and falling air that generates weather.