Answer:
Continental polar (cP) or continental arctic (cA) air masses are cold, dry, and stable. These air masses originate over northern Canada and Alaska as a result of radiational cooling. Maritime polar (mP) air masses are cool, moist, and unstable.
Explanation:
Answer:
C). 
Explanation:
As we know that capacitance of a given capacitor is

now we know that energy stored in the capacitor plates

here if all the dimensions of the capacitor plate is doubled
then in that case

here area becomes 4 times on doubling the radius and the distance between the plates also doubles
So new capacitance is now

so capacitance is doubled
now the final energy stored between the plates of capacitor is given as

so the final energy is


Answer:
The focal length of the lens should be -51.5 cm (a concave lens).
Explanation:
The purpose of the lens is to make objects at 48.5 cm appear at the healthy near point. The healthy near point is 25.0 cm.
We use the lens formula

where <em>f</em> = focal length, <em>u</em> = object distance and <em>v</em> = image distance.
In this case, <em>u</em> = 48.5 cm and <em>v</em> = -25.0 cm.
<em>v</em> is negative because the image is virtual an not real. (Here, we are using the real-is-positive sign convention)


The negative sign indicates the lens is concave.
The NUCLEUS is the center of the atom. it contains protons and NEUTRONS
protons have a POSITIVE charge
neutrons have a NEUTRAL charge
electrons have a NEGATIVE charge