Answer:
A) P1=2 [bar] , W=-12 [kJ]
B) P1=0.8 [bar] , W=-7.3303 [kJ]
C) P1=0.6077 [bar] , W=-6.4091 [kJ]
Explanation:
First, from the problem we know the following information:
V1=0.1 m^3
V2=0.04 m^3
P2=2 bar =200 kPa
The relation PV^n=constant means PV^n is a constant through all the process, so we can derive the initial pressure as:
a) To the case a) the constant n is equal to 0, we can calculate the initial pressure substituting n=0 in the previous expression, so:
The expression to calculate the work is:
If n=0:
Then:
The work is:
b) To the case b) the constant n is equal to 1, we can calculate the initial pressure substituting n=1 in the initial expression, so:
If n=1 then:
To calculate the work:
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Substituting:
c) To the case c) the constant n is equal to 1.3, we can calculate the initial pressure substituting n=1.3 in the initial expression, so:
First:
The work:
Substituting:
W=-6.4091 kJ
From our physics class, we know that Work is a product of
Force and Displacement. The force must be the force in the same direction with
the displacement. So force and displacement must be parallel.
A. How much work in J does the string do on the boy if the
boy stands still?
Since we know that: Work = Force * Displacement
and in this case displacement is equal to zero, therefore
Work must also be equal to zero.
Work = 0
B. How much work does the string do on the boy if the boy
walks a horizontal distance of 11m away from the kite?
Now are given a displacement of 11 m which is a horizontal
distance. Therefore we must first calculate the horizontal component of force:
Fx = 4.5 N * cos 30
Fx = 3.897 N
So work is:
Work = 3.897 N * 11 m
<span>Work = 42.87 J ~ 43 J</span>
Correct answer is A.
In a parallel circuit, the voltage is same across all the branches however the current in each branch is different and depends on the resistance of that branch. The higher the resistance, the lower the current.
In a series circuit, the voltage across each resistive element is different and depends on the resistance of that element. Higher the resistance, larger will be the voltage drop. However, the current throughout the series circuit is the same as there is only path in a series circuit.
Points to Remember:
1) In series circuit current remains the same and voltage varies
2) In parallel circuit voltage remains the same and current varies
Answer:
PE=0.29J
Explanation:
According to the description, there is a angle and in point swung upward of 70°
So,
Appling the equation of Potential Energy we have,