<h2>
Answer: 0.17</h2>
Explanation:
The Stefan-Boltzmann law establishes that a black body (an ideal body that absorbs or emits all the radiation that incides on it) "emits thermal radiation with a total hemispheric emissive power proportional to the fourth power of its temperature":
(1)
Where:
is the energy radiated by a blackbody radiator per second, per unit area (in Watts). Knowing
is the Stefan-Boltzmann's constant.
is the Surface area of the body
is the effective temperature of the body (its surface absolute temperature) in Kelvin.
However, there is no ideal black body (ideal radiator) although the radiation of stars like our Sun is quite close. So, in the case of this body, we will use the Stefan-Boltzmann law for real radiator bodies:
(2)
Where is the body's emissivity
(the value we want to find)
Isolating from (2):
(3)
Solving:
(4)
Finally:
(5) This is the body's emissivity
Answer:
1.8 mV
Explanation:
The total number of turns in the solenoid is
where
n = 6500 is the number of turns per meter of length
is the length of the solenoid
The flux linkage through the solenoid is given by
where
B is the strength of the magnetic field
is the cross-sectional area of the solenoid
The strength of the field in the solenoid is given by
where I is the current.
At the beginning, I = 0, so the field is
And the flux linkage is
Later, the current is I = 1.5 A, so the field in the solenoid is
So, the flux linkage is
So, the change in flux linkage is
And therefore, the emf induced in the solenoid is (in magnitude)
Answer:
less than
Explanation:
the moon has less mas and a weaker atmosphere meaning it does not have much gravitational space
Im not quite sure but it might be a or c... ill double check