What is the Relationship Between Uncertainty in Diameter and Radius?

  • Thread starter Thread starter swain1
  • Start date Start date
  • Tags Tags
    Uncertainties
Click For Summary

Homework Help Overview

The discussion revolves around the relationship between the uncertainty in the measurement of diameter and its effect on the uncertainty in radius, particularly in the context of geometric measurements. Participants are exploring how these uncertainties propagate, especially when transitioning from diameter to radius.

Discussion Character

  • Conceptual clarification, Assumption checking, Mathematical reasoning

Approaches and Questions Raised

  • Participants are attempting to determine whether the uncertainty in radius is the same as or half of the uncertainty in diameter. There is mention of a formula from Wikipedia that suggests the latter. Some participants are questioning the application of the division rule in this context and discussing the implications of using a constant in calculations.

Discussion Status

The discussion is ongoing, with some participants providing insights into the relationship between diameter and radius uncertainties. There is a request for further guidance on calculating the uncertainty in the volume of a sphere based on the radius, indicating a shift to a related but distinct topic. No consensus has been reached regarding the propagation of uncertainty in volume calculations.

Contextual Notes

Participants are working under the constraints of homework guidelines, which may limit the depth of exploration. There is an indication that some participants are unsure about the implications of their calculations and the reasons behind the expected increase in uncertainty when moving from radius to volume.

swain1
Messages
30
Reaction score
0

Homework Statement


If the uncertainty in a measurement of dameter is +-0.02cm is the uncertainty in radius the same or half of this value. The formula given in wikipedia implies that it would be half of the value.

Cheers


Homework Equations





The Attempt at a Solution

 
Physics news on Phys.org
swain1 said:

Homework Statement


If the uncertainty in a measurement of dameter is +-0.02cm is the uncertainty in radius the same or half of this value. The formula given in wikipedia implies that it would be half of the value.

Cheers


Homework Equations





The Attempt at a Solution


Yes, it will be half of this value. If the uncertainty had been given in percent form, then the percent uncertainty on the radius and on the diameter would be the same.
 
you should had this formula in your relevant equations thingy:
radius = diameter /2

2 is a number, and has uncertainty of 0
so, use division rule
 
Ok thanks guys.
I now have to work out the uncertainty in the voume of a sphere using the radius I have. Any clues on how to get the uncertainty in this value? I would expect that it would be bigger but I can't really understand why?
 
I have this formula

deltav/v=3xdeltar/r

Is this correct?
 

Similar threads

Is my textbook wrong about absolute uncertainties?
  • · Replies 2 ·
Replies
2
Views
1K
How do I calculate Heisenburg's Uncertainty Principle?
  • · Replies 16 ·
Replies
16
Views
2K
Uncertainties and the angle of minimum deviation
  • · Replies 15 ·
Replies
15
Views
2K
How do we find the uncertainty of v in the kinematics eqn?
  • · Replies 13 ·
Replies
13
Views
2K
What is the uncertainty in 5.00mm measured by analog device?
  • · Replies 1 ·
Replies
1
Views
2K
Young's modulus and uncertainty
  • · Replies 16 ·
Replies
16
Views
5K
Calculating Uncertainty when Converting Time
  • · Replies 3 ·
Replies
3
Views
4K
Experimenting whether the diameter of a pot affects boiling time for water
  • · Replies 15 ·
Replies
15
Views
3K
Percentage Uncertainties Question
  • · Replies 11 ·
Replies
11
Views
2K
What are the uncertainty values for my corrected magnitudes?
  • · Replies 2 ·
Replies
2
Views
1K