To solve the problem, it is necessary to apply the concepts related to the change of mass flow for both entry and exit.
The general formula is defined by
Where,
mass flow rate
Density
V = Velocity
Our values are divided by inlet(1) and outlet(2) by
PART A) Applying the flow equation we have to
PART B) For the exit area we need to arrange the equation in function of Area, that is
Therefore the Area at the end is 
Answer:
The number of calories needed is 6c.
Explanation:
The amount of energy 
needed to raise the temperature 
of water of mass 
is
where 
is the specific heat capacity of water.
Putting in numbers into equation (1), we get:
which is the number of calories needed.
Answer:
The planet will move from east to west for a couple of months in the night sky.
Explanation:
Retrograde motion is an optical effect due to the fact that Earth rotates more quickly than the planet that apparently has a retrograde motion in the sky.
For example, Saturn has a slower speed in its orbit around the Sun. That means that the Earth will pass it, and that will give the effect that the planet is moving backward. That same scenario can be seen between two cars on a highway, the faster car will see the slower car when it passes as it is moving for a short fragment of time in backward.
Remember that the planets in the night sky move from west to east, in the case of a planet with retrograde motion, it will move from east to west for a couple of months.
-- From January 15 to February 6 is a period of 22 days.
-- The period of the full cycle of moon phases is 29.53 days.
-- So those dates represent (22/29.53) = 74.5% of a full cycle of phases.
-- That's almost exactly 3/4 of a full cycle, so on February 6, the moon would be almost exactly at <em>Third Quarter</em>. That's the <em>left half of a disk </em>(viewed from the northern hemisphere).
True because heat energy moves to the warmer areas.
