Answer:
As the planets are very small and dark in comparison with stars, it makes them very hard to be found from earth.
Explanation:
Astronomy, of course, has a solution for this. As astronomers can't observe planets directly, they decided to observe the stars and search for the effects that planets have on them.
There are many ways of observing the exoplanets: Radial Velocity, Transit Photometry, Microlensing, Astrometry, Direct Imaging, etc.
Before all of this, scientist had to find ways to prove their theories. Most of their time they have spent in giving the creative answers.
Science and creativity are very much connected when we speak about the development of science. Rationality and creativity always go together.
In order to create an idea that other people will consider useful, it is important to use creativity. As no one has the exact answer when it comes to science, the adventure is to research the unknown.
Answer:
2.58 x 10⁸ m/s
Explanation:
Time dilation fomula will be applicable here, which is given below.
t = \frac{T}{\left ( 1-\frac{v^2}{c^2} \right )^\frac{1}{2}}
Where T is dilated time or time observed by clock in motion , t is stationary time , v is velocity of clock in motion and c is velocity of light .
c is 3 times 10⁸ ms⁻¹ , T is 7.24 h , t is 3.69 h. Put these values in the formula
7.24 = \frac{3.69}{\left ( 1-\frac{v^2}{c^2} \right )^\frac{1}{2}}\\
\frac{v^2}{c^2}=0.744\\\\
v=2.58\times 10^8
The amount of heat needed to increase the temperature of a solid sphere of diameter 2D of the same metal from 4°C to 7°C is is 8 times the initial amount of heat.
<h3>What is heat?</h3>
The temperature increment will lead to the increase in the internal energy of the object. This internal energy is the heat.
Given is the change in temperature ΔT = 7-4 =3°C., diameter D to 2D,
Q = Cp x ρ(4π/3)D³ x 3..................(1)
and Q' = Cp x ρ(4π/3)(2D)³ x 3
Q' = Cp x ρ(4π/3)8D³x 3..................(2)
Dividing both the equation, we have
Q' / Q =8
Q' = 8Q
Thus, the amount of heat needed to increase the temperature of a solid sphere of diameter 2D of the same metal from 4°C to 7°C is 8 times the initial amount of heat.
Learn more about heat.
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Answer:
v = 2,99913 10⁸ m / s
Explanation:
The velocity of propagation of a wave is
v = λ f
in the case of an electromagnetic wave in a vacuum the speed that speed of light
v = c
When the wave reaches a material medium, it is transmitted through a resonant type process, whereby the molecules of the medium vibrate at the same frequency as the wave, as the speed of the wave decreases the only way that they remain the relationship is that the donut length changes in the material medium
λ = λ₀ / n
where n is the index of refraction of the material medium.
Therefore the expression is
v = 
Let's look for the frequency of blue light in a vacuum
f =
f = 
f = 6.667 10¹⁴ Hz
the refractive index of air is tabulated
n = 1,00029
let's calculate
v = 
450 10-9 / 1,00029 6,667 1014
v = 2,99913 10⁸ m / s
we can see that the decrease in speed is very small
