<span>The question is asking us what is BEST to say about a runner who is running at a constant velocity? A constant velocity (=speed) means that they are not getting faster or slower - they are running exactly as fast all the time. This meanst that their speed does not change, so their change of speed is equal to 0. A change of speed is called acceleration so their C. Their acceleration is zero. - C is the correct answer. </span>
Not sure about 21, but the 1738 is a turned used by a rapper named Fetty Wap in his song called Trap Queen to represent the "Remy Boyz 1738" which they named themselves that after the finest 1738 Remy Martin liquor.
Hope that helps you! :)
The correct answer is A.
The cell membrane consists of a phospholipid bilayer with embedded proteins. Sometimes molecules are just too big to easily flow across the plasma membrane or dissolve in the water so that they can be filtered through the cell membrane. In these cases , the cells must put out a little energy to help get molecules in and out of the cell.
The proteins embedded in the plasma membrane form channels through which other molecules can pass. Some proteins act as carriers, that is they are 'paid" in energy to let a molecule attach to itself and then transport that molecule inside the cell. This is called active transport.
Answer:
an air mass is a volume of air defined by its temperature and water vapor content. Air masses cover many hundreds or thousands of miles, and adapt to the characteristics of the surface below them. They are classified according to latitude and their continental or maritime source regions. Colder air masses are termed polar or arctic, while warmer air masses are deemed tropical. Continental and superior air masses are dry while maritime and monsoon air masses are moist. Weather fronts separate air masses with different density (temperature and/or moisture) characteristics. Once an air mass moves away from its source region, underlying vegetation and water bodies can quickly modify its character.When winds move air masses, they carry their weather conditions (heat or cold, dry or moist) from the source region to a new region. When the air mass reaches a new region, it might clash with another air mass that has a different temperature and humidity. This can create a severe storm.
Air masses can affect the weather because of different air masses that are different in temperature, density, and moisture. When two different air masses meet a front forms. This is one way air masses effect our weather.
