| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.49 |
| Score | 0% | 70% |
Earth's breathable air is held in which atmospheric layer?
mesosphere |
|
thermosphere |
|
stratosphere |
|
troposphere |
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.
Velocity is the rate at which an object changes position. What is the formula for velocity?
\(\vec{v} = { \vec{d} \over t } \) |
|
\(\vec{v} = \vec{d}t \) |
|
\(\vec{v} = { t \over \vec{d} } \) |
|
none of these |
Velocity is the rate at which an object changes position. Rate is measured in time and position is measured in displacement so the formula for velocity becomes \(\vec{v} = { \vec{d} \over t } \)
A major difference between sound waves and light waves is which of the following?
a sound wave is mechanical while a light wave is electromagnetic |
|
a sound wave cannot travel through a vacuum |
|
a sound wave is much slower than a light wave |
|
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.
The hottest of Earth's atmospheric layers is which of the following?
troposphere |
|
thermosphere |
|
stratosphere |
|
mesosphere |
Temperatures again increase with altitude in the thermosphere which is the hottest (4,530 °F / 2,500 °C) atmospheric layer due to direct exposure to the Sun's radiation. However, the gas in this layer is highly diluted so even though the atoms of gas may be very high in temperature, there are too few of them to effectively transfer much heat.
Minerals, vitamins, and fiber are:
macronutrients |
|
carbohydrates |
|
micronutrients |
|
proteins |
Minterals, vitamins, and fiber are micronutrients while proteins, carbohydrates, and fats are macronutrients.