Answer:
The farther star will appear 4 times fainter than the star that is near to the observer.
Explanation:
Since it is given that the luminosity of the 2 stars is same thus they radiate the same energy per unit time
Consider a spherical wave front of energy 'E' that leaves both the stars (Both radiate 'E' as they have same luminosity)
This Energy is spread over the whole surface area of sphere Thus when the wave front is at a distance 'r' the energy per unit surface area is given by

For the star that is twice away from the earth the distance is '2r' thus we will receive an energy given by
Hence we sense it as 4 times fainter than the nearer star.
The acceleration of a 600,000 kg freight train, if each of its three engines can provide 100,000N of force is 0.167m/s².
<h3>How to calculate acceleration?</h3>
The acceleration of a freight train can be calculated using the following formula:
Force = mass × acceleration
According to this question, a 600,000kg freight train can produce 100,000N of force. The acceleration is as follows:
100,000 = 600,000 × a
100,000 = 600,000a
a = 0.167m/s²
Therefore, the acceleration of a 600,000 kg freight train, if each of its three engines can provide 100,000N of force is 0.167m/s².
Learn more about acceleration at: brainly.com/question/12550364
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Diagram 4 is the correct answer.
I think it’s R=U/I = 120/5 = 24