If a star is a brilliant blue color, it's really hot and emits a lot of energy. If it's red, it has a cool surface temperature instead. Therefore, the dominant wavelength of a star's light can tell us its surface temperature.
Answer:
Explanation:
As we know that diameter of hand crank is given as
Also the diameter of the shaft on which the rope is wound is given as
now we know that both are moving with same angular speed
so we will have
so we will have
The shining of the moon at night is the reflection of the sun bouncing off the surface of the moon. That is why we on Earth can see the moon appear as shining.
Answer:
B.
Explanation:
When equal forces are exerted onto eachother, they are exerting equal pressure since they are stationary.
Answer:
#_photon = 5 10²⁰ photons / s
Explanation:
For this exercise let's calculate the energy of a single quantum of energy, use Planck's law
E = h f
c= λ f
E = h c / λ
λ= 1000 nm (1 m / 109 nm) = 1000 10⁻⁹ m
Let's calculate
E₀ = 6.6310⁻³⁴ 3 10⁸/1000 10⁻⁹
E₀ = 19.89 10⁻²⁰ J
This is the energy emitted by a photon let's use a proportions rule to find the number emitted in P = 100 w
#_photon = P / E₀
#_photon = 100 / 19.89 10⁻²⁰
#_photon = 5 10²⁰ photons / s