A campfire being lighted and plants converting carbon-dioxide and water into glucose and oxygen are both forms of chemical change.
Therefore, the answer is:
B. Both are examples of chemical change.
Answer:
Explanation:
1. We can find the temperature of each star using the Wien's Law. This law is given by:
(1)
So, the temperature of the first and the second star will be:
![T_{1}=3866.7 K](https://tex.z-dn.net/?f=T_%7B1%7D%3D3866.7%20K)
![T_{2}=6444.4 K](https://tex.z-dn.net/?f=T_%7B2%7D%3D6444.4%20K)
Now the relation between the absolute luminosity and apparent brightness is given:
(2)
Where:
- L is the absolute luminosity
- l is the apparent brightness
- r is the distance from us in light years
Now, we know that two stars have the same apparent brightness, in other words l₁ = l₂
If we use the equation (2) we have:
![\frac{L_{1}}{4\pi r_{1}^2}=\frac{L_{2}}{4\pi r_{2}^2}](https://tex.z-dn.net/?f=%5Cfrac%7BL_%7B1%7D%7D%7B4%5Cpi%20r_%7B1%7D%5E2%7D%3D%5Cfrac%7BL_%7B2%7D%7D%7B4%5Cpi%20r_%7B2%7D%5E2%7D)
So the relative distance between both stars will be:
(3)
The Boltzmann Law says,
(4)
- σ is the Boltzmann constant
- A is the area
- T is the temperature
- L is the absolute luminosity
Let's put (4) in (3) for each star.
![\left(\frac{d_{1}}{d_{2}}\right)^{2}=\frac{A_{1}\sigma T_{1}^{4}}{A_{2}\sigma T_{2}^{4}}](https://tex.z-dn.net/?f=%5Cleft%28%5Cfrac%7Bd_%7B1%7D%7D%7Bd_%7B2%7D%7D%5Cright%29%5E%7B2%7D%3D%5Cfrac%7BA_%7B1%7D%5Csigma%20T_%7B1%7D%5E%7B4%7D%7D%7BA_%7B2%7D%5Csigma%20T_%7B2%7D%5E%7B4%7D%7D)
As we know both stars have the same size we can canceled out the areas.
![\left(\frac{d_{1}}{d_{2}}\right)^{2}=\frac{T_{1}^{4}}{T_{2}^{4}}](https://tex.z-dn.net/?f=%5Cleft%28%5Cfrac%7Bd_%7B1%7D%7D%7Bd_%7B2%7D%7D%5Cright%29%5E%7B2%7D%3D%5Cfrac%7BT_%7B1%7D%5E%7B4%7D%7D%7BT_%7B2%7D%5E%7B4%7D%7D)
![\frac{d_{1}}{d_{2}}=\sqrt{\frac{T_{1}^{4}}{T_{2}^{4}}}](https://tex.z-dn.net/?f=%5Cfrac%7Bd_%7B1%7D%7D%7Bd_%7B2%7D%7D%3D%5Csqrt%7B%5Cfrac%7BT_%7B1%7D%5E%7B4%7D%7D%7BT_%7B2%7D%5E%7B4%7D%7D%7D)
I hope it helps!
Answer ) Sound level equation
The intensity of a sound wave is related to its amplitude squared by the following relationship: I=(Δp)22ρvw I = ( Δ p ) 2 2 ρ v w . Here Δp is the pressure variation or pressure amplitude (half the difference between the maximum and minimum pressure in the sound wave) in units of pascals (Pa) or N/m2.
Answer:
A) The wave that travels through the rail reaches the microphone first.
B) separation in time between the arrivals of the two pulses is 0.01539 seconds.
Explanation:
Detailed explanation and calculation is shown in the image below
A) if energy is being absorbed, then more hydrogen bonds are being broken (melting). If energy is being released, more hydrogen bonds become fixed (freezing).
<span>b) during melting, hydrogen bonds get broken and movement can occur. During freezing, hydrogen bonds become fixed and water molecules cannot move as much.
I hope my answer has come to your help. Thank you for posting your question here in Brainly. We hope to answer more of your questions and inquiries soon. Have a nice day ahead!</span>