How Much Energy Can We Obtain from 211g of Peanuts?

  • Thread starter Thread starter Hannah1
  • Start date Start date
  • Tags Tags
    Energy
AI Thread Summary
The discussion revolves around calculating the energy obtainable from 211 grams of peanuts using Einstein's equation E=mc². The initial calculation mistakenly yielded 7.22E18 Joules, but after correcting the input, the correct energy value was determined to be 1.90E16 Joules. Participants confirmed the accuracy of the revised calculation. The conversation highlights the importance of careful input in calculations. Overall, the correct energy derived from 211 grams of peanuts is 1.90E16 Joules.
Hannah1
Messages
47
Reaction score
0

Homework Statement


How much energy can we obtain from 211g of peanuts. (Remember c = speed of light = 3 E 8 m/s) Remember to write your answer to two decimal places and for example 4.56x10^8 must be written as 4.56E8

Homework Equations


E = mc2
c = 300,000,000 m/sec

The Attempt at a Solution


211 g = 0.211 kg
E = (0.211)(300,000,000)2
E = 7.21899e+18

Energy = 7.22E18 Joules

Am I correct??
 
Last edited:
Physics news on Phys.org
Hi Hannah1! :smile:
Hannah1 said:
E = (0.211)(300,000,000)2
E = 7.21899e+18

You seem to have entered 80.211 into your calculator. :wink:
 
tiny-tim said:
Hi Hannah1! :smile:You seem to have entered 80.211 into your calculator. :wink:

You're right! My bad. I tried again and this is what I got:
E = (0.211)(300,000,000)2
E = 1.899e+16

Therefore, Energy = 1.90E16 Joules.

Am I correct now??
 
(just got up :zzz:)
Hannah1 said:
You're right! My bad. I tried again and this is what I got:
E = (0.211)(300,000,000)2
E = 1.899e+16

Therefore, Energy = 1.90E16 Joules.

Am I correct now??

he he :biggrin:

yes :smile:
 
tiny-tim said:
(just got up :zzz:)


he he :biggrin:

yes :smile:


Thank you! :smile:
 
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 .
TL;DR Summary: I came across this question from a Sri Lankan A-level textbook. Question - An ice cube with a length of 10 cm is immersed in water at 0 °C. An observer observes the ice cube from the water, and it seems to be 7.75 cm long. If the refractive index of water is 4/3, find the height of the ice cube immersed in the water. I could not understand how the apparent height of the ice cube in the water depends on the height of the ice cube immersed in the water. Does anyone have an...
Back
Top