Ocr practical paper question on concept

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The discussion centers on the concept of uncertainty in measurements when stacking disks for an exam question. It argues that adding more disks increases uncertainty, suggesting that a maximum of 9 disks should be used to maintain less than 0.5% uncertainty. However, it's clarified that the scale's resolution of 0.2 grams remains constant regardless of the number of disks. As more disks are added, the uncertainty per disk actually decreases, leading to the conclusion that 10 disks can be used without exceeding the uncertainty threshold. The key takeaway is that the scale's resolution allows for the use of 10 disks while maintaining acceptable uncertainty levels.
bonbon22
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Homework Statement
problem statemetn below
Relevant Equations
volume = surface area of sphere * thickness
percentage uncertainty = absolute uncertainty/ value
244275

should n't it be a maximum number to achieve less than 0.5% uncertainty for the last question as you add more disks would there not be more uncertanity therefore as the number of disks for 0.5% is 9.5, 10 would give an unceranity of greater than 0.5% so it should be 9? the answer is 10.
 
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What's an ocr? Optical character recognition?
 
berkeman said:
What's an ocr? Optical character recognition?
Exam broad,, for a levels . IF you got free time friend would be grateful if you could help me out.
 
bonbon22 said:
should n't it be a maximum number to achieve less than 0.5% uncertainty for the last question as you add more disks would there not be more uncertanity therefore as the number of disks for 0.5% is 9.5, 10 would give an unceranity of greater than 0.5% so it should be 9? the answer is 10.
An implicit assumption going in is that the discs are identical.

The uncertainty is from the limited resolution of the scale: 0.2 grams. As specified, the scale's resolution is independent of how many discs you pile on. The more you pile on, the lower the uncertainty per disk.
 
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The book claims the answer is that all the magnitudes are the same because "the gravitational force on the penguin is the same". I'm having trouble understanding this. I thought the buoyant force was equal to the weight of the fluid displaced. Weight depends on mass which depends on density. Therefore, due to the differing densities the buoyant force will be different in each case? Is this incorrect?

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