Power developed by a person on eating 100g of ice per minute is?

  • Thread starter Thread starter Mimosapudica
  • Start date Start date
  • Tags Tags
    Ice Per Power
AI Thread Summary
The discussion revolves around calculating power from the process of eating ice, using the formula P=W/t. The initial calculation yielded a power output of 0.56 watts, but a participant pointed out a discrepancy, suggesting the answer should be 560 J/s, indicating a factor of 1000 error. The confusion arose from the conversion of grams to kilograms, which was not properly addressed. It was later clarified that the latent heat value of 80 cal/g did not require conversion, resolving the error. The conversation emphasizes the importance of using consistent SI units in calculations.
Mimosapudica
Messages
11
Reaction score
1
Homework Statement
Power generated is the work done per unit time. Also latent heat of ice is 80cal.
Relevant Equations
P=W/t
W= Energy = heat generated ?
Heat Q= mass x latent heat
P=W/t
W=Q= mL = (100x 80x 4.2)/1000 (kg x J/kg)
= 33.6
t= 1 minute= 60s
P= 33.6/60= 0.56 watt...
but the answer provided is 560J/s...?
 
Physics news on Phys.org
Looks like you are out by a factor of 1000. What's usually the reason for that?
 
PeroK said:
Looks like you are out by a factor of 1000. What's usually the reason for that?
I’m guessing the g to kg conversion has some problem, but shouldn’t we be converting it?
 
Mimosapudica said:
I’m guessing the g to kg conversion has some problem, but shouldn’t we be converting it?

Why don't you first write down all the quantities involved in SI units?
 
  • Like
Likes berkeman
PeroK said:
Looks like you are out by a factor of 1000. What's usually the reason for that?

Oops.. latent heat is 80 cal/g .. So it doesn’t need conversation.. that was a careless error.. thank you.
 
  • Like
Likes berkeman
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 .
Thread 'Voltmeter readings for this circuit with switches'
TL;DR Summary: I would like to know the voltmeter readings on the two resistors separately in the picture in the following cases , When one of the keys is closed When both of them are opened (Knowing that the battery has negligible internal resistance) My thoughts for the first case , one of them must be 12 volt while the other is 0 The second case we'll I think both voltmeter readings should be 12 volt since they are both parallel to the battery and they involve the key within what the...
Back
Top