B. the distance the star is from Earth
Explanation:
The apparent magnitude of star is a function of its distance from the earth. It is one of the physical properties that is used to study a star.
The apparent magnitude of a star or other astronomical bodies is a measure of their brightness as seen from a location on the earth.
The apparent magnitude of a star depends on:
- Distance of the star from the location on earth.
- luminosity of the star
- the particles along the part of the star and earth that cuts off the light the earth receives.
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Star luminosity brainly.com/question/9084808
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The area of the Earth (Ae) that is irradiated by is given by:
Ae = 4πRe^2, where Re = Distance from Sun to Earth
Substituting;
Ae = 4π*(1.5*10^8*1000)^2 = 2.827*10^23 m^2
On the Earth, insolation (We) = Psun/Ae
Therefore,
Psun (Rate at which sun emits energy) = We*Ae = 1.4*2.827*10^23 = 3.958*10^23 kW = 3.958*10^26 W
Answer:
option E
Explanation:
given,
diameter = 4 mm
shutter speed = 1/1000 s
diameter of aperture = ?
shutter speed = 1/250 s
exposure time to the shutter time

N is the diameter of the aperture and t is the time of exposure
now,


inserting all the values

N₂² = 4
N₂ = 2 mm
hence , the correct answer is option E
Blood
I learned this in anatomy, and I've taken it twice