Answer:
The charge density in the system is 
Explanation:
To solve this problem it is necessary to keep in mind the concepts related to current and voltage through the density of electrons in a given area, considering their respective charge.
Our data given correspond to:
We need to asume here the number of free electrons in a copper conductor, at which is generally of 
The equation to find the current is
Where
I =Current
V=Velocity
A = Cross-Section Area
e= Charge for a electron
n= Number of free electrons
Then replacing,
Now to find the linear charge density, we know that
Where:
I: current intensity
Q: total electric charges
t: time in which electrical charges circulate through the conductor
And also that the velocity is given in proportion with length and time,
The charge density is defined as
Replacing our values
Therefore the charge density in the system is
Because gas particles in the air like particles of all fluids are constantly moving and bumping into things, they exert pressure. The pressure exerted by the air in the atmosphere is greater close to Earth's surface and decreases as you go higher above the surface.
<u>Explanation</u>:
- Fill roughly one-third of a cup with water. Then, cover the mouth of the cup completely with a flat, hard cardboard. Using your hand to keep it in place, turn the cup upside down. When you remove your hand, the the cardboard stays in place.
-
One would expect that due to gravity, the water will fall, and even the cardboard will. However, it does not, which means that something must be applying an upward force on the cardboard. This is nothing other than air pressure, which applies a force across the surface of the cardboard in an upward direction.
- Thus we can demonstrate that air exerts pressure, because otherwise, the water would have fallen.
k = 1/2 × m × v^2
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1. k = 1/2 × 60 × ( 10 )^2
k = 30 × 100
k = 3000 j
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2. k = 1/2 × 60 × ( 9 )^2
k = 30 × 81
k = 2430 j
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3. k = 1/2 × 60 × ( 4 )^2
k = 30 × 16
k = 480 j
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4. k = 1/2 × 60 × ( 6 )^2
k = 30 × 36
k = 1080 j
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5. k = 1/2 × 60 × ( 0 ) ^2
k = 30 × 0
k = 0 j
