Answer:
it is True as the operational definition of electric current.
Explanation:
The definition of electric current is
I = dQ / dt
By convention the direction of the current is the direction in which a positive charge flows.
The initial expression is the derivative that is the change of the load in the unit of time and this occurs in a given cross-sectional cable.
The proposed definition is the same as this, so it is True as the operational definition of electric current.
I have the exact same question, any chance you figured it out since you posted this?
Answer:
5.44×10⁶ m
Explanation:
For a satellite with period t and orbital radius r, the velocity is:
v = 2πr/t
So the centripetal acceleration is:
a = v² / r
a = (2πr/t)² / r
a = (2π/t)² r
This is equal to the acceleration due to gravity at that elevation:
g = MG / r²
(2π/t)² r = MG / r²
M = (2π/t)² r³ / G
At the surface of the planet, the acceleration due to gravity is:
g = MG / R²
Substituting our expression for the mass of the planet M:
g = [(2π/t)² r³ / G] G / R²
g = (2π/t)² r³ / R²
R² = (2π/t)² r³ / g
R = (2π/t) √(r³ / g)
Given that t = 1.30 h = 4680 s, r = 7.90×10⁶ m, and g = 30.0 m/s²:
R = (2π / 4680 s) √((7.90×10⁶ m)³ / 30.0 m/s²)
R = 5.44×10⁶ m
Notice we didn't need to know the mass of the satellite.
Answer: D.) increasing in distance from the earth
Explanation:
The <u>Doppler shift</u> is related to the Doppler effect and refers to the change in a wave perceived frequency (or <u>wavelength=color</u>) when the emitter of the waves, and the observer move relative to each other.
From there, it is deduced that the farther the object is, the more redshifted it is in its spectrum. For example, <u>as a galaxy moves away from the Earth, its espectrum turns towards the red and as the galaxy moves toward the Earth, its espectrum turns towards the blue.
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It should be noted that this effect bears its name in honor of the Austrian physicist Christian Andreas Doppler, who in 1842 proposed the existence of this effect for the case of light in the stars.
