| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.16 |
| Score | 0% | 63% |
Earth's troposphere layer is which of the following?
closest to the surface |
|
coldest |
|
farthest from the surface |
|
hottest |
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.
Which part of the respiratory system helps protect against infection?
pharynx |
|
trachea |
|
epiglottis |
|
nasal cavity |
After air enters through the nose, it passes through the nasal cavity which filters, moistens, and warms it. Further filtering takes place in the pharynx, which also helps protect against infection, and then in the trachea which is just past the epiglottis, responsible for preventing food from entering the airway.
The heat from the Sun traveling to Earth is an example of which of the following?
electricity |
|
convection |
|
conduction |
|
radiation |
Radiation occurs when electromagnetic waves transmit heat. An example is the heat from the Sun as it travels to Earth.
Small rocks shed by asteroids and comets that reach the earth are called:
meteorites |
|
meteoroids |
|
meteors |
|
shooting stars |
Smaller rocks shed by asteroids and comets are called meteoroids. When these rocks reach Earth's atmosphere, they burn up in the mesosphere and become meteors. If a meteor manages to reach the Earth, it is called a meteorite.
Sound travels fastest through which of the following media?
air |
|
vacuum |
|
water |
|
metal |
The speed of a sound wave will vary with the medium. Sound travels fastest through media that has particles that are very close together, like metal. Thus, it travels faster through water than through air and doesn't travel at all through a vacuum (there are no particles in empty space to vibrate).