Calculating Energy from Intensity: A Super Nova Scenario

  • Thread starter Thread starter Aeighme
  • Start date Start date
  • Tags Tags
    Energy Intensity
AI Thread Summary
A supernova releases 2.0×10^45 J of energy, and the scenario involves calculating how much energy reaches a 7 cm radius face located 1500 light-years away. The intensity of the energy is calculated using the formula I=P/A, but it becomes evident that this formula is not directly applicable since the total energy, rather than power, is given. The discussion highlights confusion about how to relate intensity to the energy received on the face, emphasizing the need for a different equation to connect these concepts. Participants express the challenge of finding the correct relationship in their study materials. The conversation underscores the importance of understanding the distinction between energy and power in astrophysical calculations.
Aeighme
Messages
25
Reaction score
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.
 
Physics news on Phys.org
Assume that the energy is uniformly distributed over the face of a sphere of radius 1500 ly.
 
but which equation would connect the energy to the intensity? =/
 
I = P / A isn't relevant here. You are given the total energy released, not the power (rate of energy release).
 
oh, well I feel silly.
hopefully I can find the equation I should use in my book.
 

Thread 'Rolling without slipping on a curved surface'

Kindly see the attached pdf. My attempt to solve it, is in it. I'm wondering if my solution is right. My idea is this: At any point of time, the ball may be assumed to be at an incline which is at an angle of θ(kindly see both the pics in the pdf file). The value of θ will continuously change and so will the value of friction. I'm not able to figure out, why my solution is wrong, if it is wrong .
View full post »
Thread 'Trying to understand the logic behind adding vectors with an angle between them'

Thread 'Trying to understand the logic behind adding vectors with an angle between them'

My initial calculation was to subtract V1 from V2 to show that from the perspective of the second aircraft the first one is -300km/h. So i checked with ChatGPT and it said I cant just subtract them because I have an angle between them. So I dont understand the reasoning of it. Like why should a velocity be dependent on an angle? I was thinking about how it would look like if the planes where parallel to each other, and then how it look like if one is turning away and I dont see it. Since...
View full post »
Thread 'Correct statement about a reservoir with an outlet pipe'

Thread 'Correct statement about a reservoir with an outlet pipe'

The answer to this question is statements (ii) and (iv) are correct. (i) This is FALSE because the speed of water in the tap is greater than speed at the water surface (ii) I don't even understand this statement. What does the "seal" part have to do with water flowing out? Won't the water still flow out through the tap until the tank is empty whether the reservoir is sealed or not? (iii) In my opinion, this statement would be correct. Increasing the gravitational potential energy of the...
View full post »

Similar threads

How much energy would enter your pupils from an explosion in space?
Replies
2
Views
1K
Intensity of sound wave and energy
Replies
1
Views
2K
How does reflection affect the intensity of the microwave?
Replies
2
Views
3K
Intensity of Stars and the Inverse Square Law Problem
Replies
10
Views
3K
Special Relativity: Super-Novae light on earth
Replies
2
Views
2K
Supernova energy reached by detector disk 1560 light years away
Replies
2
Views
4K
Calculating Power at source from Intensity at distance R
Replies
1
Views
4K
Energy from the Sun received at the Earth cross section
Replies
2
Views
2K
How is Wave Intensity Calculated?
Replies
6
Views
2K
Solar Panels and Solar Radiation Flux Density Help - Very Confused
Replies
35
Views
5K

Hot Threads

Recent Insights

Back
Top