Question

question 3
the ____ is zero at the equator and increases with latitude.
a pgf = pressure gradient force
b cf = coriolis force
c fr = frictional force
d gr = gravitational force

question 4
the ____ is always directed toward the lower values of pressure.
a pgf = pressure gradient force
b cf = coriolis force
c fr = frictional force
d gr = gravitational force

Explanation:

• Question 3: The Coriolis Force (\(CF\)) is zero at the equator because the Coriolis parameter \(f = 2\Omega\sin\varphi\) (where \(\Omega\) is the Earth's angular velocity and \(\varphi\) is the latitude). When \(\varphi = 0^{\circ}\) (at the equator), \(f=0\). As latitude \(\varphi\) increases (either north or south of the equator), \(\sin\varphi\) increases, so the Coriolis Force increases. The Pressure Gradient Force (\(PGF\)) depends on pressure differences, the Frictional Force (\(FR\)) depends on wind - surface interactions, and the Gravitational Force (\(GR\)) is relatively constant over short latitudinal distances compared to the Coriolis Force variation.
• Question 4: The Pressure Gradient Force (\(PGF\)) is defined as \(PGF=-\frac{1}{

ho}
abla p\) (where \(
ho\) is air density and \(
abla p\) is the pressure gradient vector). The negative sign indicates that the force is directed from high - pressure to low - pressure regions. The Coriolis Force is perpendicular to the wind direction (in the Northern Hemisphere, to the right of the wind direction and to the left in the Southern Hemisphere), the Frictional Force is opposite to the wind direction, and the Gravitational Force is directed towards the center of the Earth.

Answer:

Question 3: B. CF = Coriolis Force
Question 4: A. PGF = Pressure Gradient Force