Which of the following fields push on a stationary electron?(A) electric and gravitational fields but not magnetic fields. (B) g
2 answers:
Answer:
(A) electric and gravitational fields but not magnetic fields.
Explanation:
Let's analyze the effect produced by each of the three fields on the stationary electron:
- Gravitational force: the gravitational force exerted on the electron by a gravitational field is
where
m is the mass of the electron
g is the strength of the gravitational field
Since the mass of the electron m is non-zero, the electron experiences a gravitational force.
- Electric field: the electric force exerted on the electron by an electric field is
where
q is the charge of the electron
E is the magnitude of the electric field
Since the charge q of the electron is non-zero, the electron experiences an electric force.
- Magnetic field: the magnetic force exerted on the electron by a magnetic field is
where
q is the electron charge
v is the velocity of the electron
B is the magnitude of the magnetic field
is the angle between the direction of v and B
Since the electron is stationary, we notice that the velocity is zero: v=0, therefore the magnetic force is zero as well.
Therefore, the correct answer is
(A) electric and gravitational fields but not magnetic fields.
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<h2>Answer: its temperature must increase.</h2>
Explanation:
In an isobaric process the pressure remains constant, which means the initial pressure and the final pressure will be the same.
In addition, during this thermodynamic process, the volume of the ideal gas expands or contracts in such a way that the variation of pressure is neutralized.
Now, according to the First law of Thermodynamics that establishes the conservation of energy:
(1)
Where:
is the internal energy
is the heat transferred
is the work
Now, for an isobaric process:
(2)
Where:
is the pressure (<u>always positive</u>)
is the volume variation of the gas
<u />
<u>Here we have two possible results:</u>
-If the gas expands (positive ), the work is positive.
-If the gas compresses (negative ), the work is negative.
In this case we are talking about the first result (work is positive).
Then, according to the above, equation (1) can be written as follows:
(3)
Clearing :
(4)
Then, for an ideal gas in an isobaric process, part of the heat () added to the system will be used to do work (positive in this case) and the other part <u>will increase the internal energy</u>, hence <u>the temperature will increase as well.</u>