Calculating Energy from Intensity: A Super Nova Scenario

In summary, a super nova located 1500 ly from earth releases 2.0×1045 J of energy. The question asks how much energy would reach a person's face if they were facing the star and their face was a circle with a radius of 7 cm. The solution involves finding the equation that connects the total energy released to the intensity of the sun at the point of the face. The equation I=P/A is not relevant here since the total energy is given, not the power. The correct equation can be found in the book.
  • #1
Aeighme
25
0

Homework Statement


A super nova releases 2.0×1045 J of energy. It is 1500 ly from earth. If you were facing the star in question, and your face was a circle 7 cm in radius, how much energy would reach your face?


Homework Equations


I=P/A


The Attempt at a Solution


I used I=P/A to get the intensity of the sun at the point of the face, but was unsure of how to use that number to determine the energy on 'my' face.
 
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  • #2
Assume that the energy is uniformly distributed over the face of a sphere of radius 1500 ly.
 
  • #3
but which equation would connect the energy to the intensity? =/
 
  • #4
I = P / A isn't relevant here. You are given the total energy released, not the power (rate of energy release).
 
  • #5
oh, well I feel silly.
hopefully I can find the equation I should use in my book.
 

Related to Calculating Energy from Intensity: A Super Nova Scenario

1. What is the difference between energy and intensity?

Energy refers to the ability to do work or cause change, while intensity is the strength or magnitude of energy. In other words, energy is the potential to do something, while intensity is the measure of how much energy is actually being used or transferred.

2. How is energy and intensity measured?

Energy is typically measured in joules (J) or calories (cal), while intensity is measured in watts (W) or decibels (dB). The specific units used may vary depending on the type of energy or intensity being measured.

3. What factors affect the energy and intensity of a system?

The energy and intensity of a system can be affected by a variety of factors, including the type of energy being used, the amount of energy being input into the system, the efficiency of the system, and external factors such as temperature, pressure, and friction.

4. How are energy and intensity related?

Energy and intensity are closely related, as intensity is a measure of the strength or magnitude of energy. In some cases, an increase in energy will result in a corresponding increase in intensity, while in others, the relationship may be more complex.

5. What are some real-world applications of the energy and intensity problem?

The energy and intensity problem has many real-world applications, such as in designing more efficient energy systems, understanding the effects of energy on the environment, and developing safety measures for high-intensity energy sources such as nuclear power plants and lasers.

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