We need to directly measure the spectral type in order to determine the surface temperature of a star.
<h3>How do you find the properties of a star?</h3>
Astronomers can determine the temperature of a star by looking at its color and spectrum. The apparent brightness of a star describes how luminous it looks to us. The brightness of a star tells us how bright it really is. The luminance can be determined using both the perceived brightness and the distance.
A star's luminosity, or the total amount of energy it emits each second, is determined by two factors: The stellar photosphere's "Effective Temperature," T. the star's total surface area, which is influenced by its radius, R.
Because it controls how much fuel a star has and how quickly it burns it, a star's mass is its most fundamental characteristic. The majority of a star's life is spent burning hydrogen into helium in its core, which generates energy. The star needs to achieve a balance between gravity and outward pressure in order to continue to be "alive."
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Mass= density x volume
1.3 kg/m^3 x ( 2.5x4x10) m^3
= 130 kg
Answer: Option (b) is the correct answer.
Explanation:
The given data is as follows.
F = 
N
g = 9.8 m/s
radius = 
= 
= 15 cm = 0.15 m (as 1 m = 100 cm)
Formula to calculate depth is as follows.
F = 
or, h = 
h = 
= 751 m
Thus, we can conclude that the maximum depth in a lake to which the submarine can go without damaging the window is closest 750 m.
