Propogation of uncertainty in a data set (finger-math at most)

In summary, the speaker has conducted a lab to measure the distance traveled by a falling weight in certain time intervals and calculate its velocity. They then graphed velocity versus time to determine acceleration, which was close to the expected value of g. The speaker is unsure about calculating uncertainty for velocity, acceleration, and the y-intercept of the velocity versus time graph. They mention that absolute uncertainties for time and distance are given and ask if a single relative uncertainty can be used for the entire data set or if it needs to be calculated for each data point. They also question if they are missing any concepts in this calculation.
  • #1
ZamielTheGrey
9
0

Homework Statement


I have conducted a simple lab, that involves getting the distance traveled by a vertically falling weight at certain time intervals. Velocity is calculated for every time interval (distance traveled per time interval). Then I graph velocity versus time to get acceleration which comes out decently close to g.

Now the part I am confused about is calculating uncertainty for:
a) Velocity
b) Acceleration
c) y-intercept of velocity vs. time graph (acceleration line)

Absolute uncertainty for time is +-0.010s, and +-0.001m (1mm) for distance.

Homework Equations


Relative uncertainty % = Absolute Uncertainty / Measured value
* and / of uncertainties with each other adds their relative uncertainties

The Attempt at a Solution


Since this is of a data set, you have many measured values, and it makes no sense to have a single relative uncertainty in the above equation. It would be different for each data point, correct?

Am I missing something from this concept? Or do I literally have to calculate out a different uncertainty for each velocity? Another possibility could be finding relative uncertainty for the first data point and using that % throughout the problem for all of them but that can't be right...
 
Physics news on Phys.org
  • #2
mump
 

Related to Propogation of uncertainty in a data set (finger-math at most)

1. How is uncertainty in a data set calculated?

Uncertainty in a data set is typically calculated using statistical methods such as standard deviation, standard error, or confidence intervals.

2. What is the importance of understanding uncertainty in a data set?

Understanding uncertainty in a data set is crucial for accurately interpreting and drawing conclusions from the data. It helps to account for any potential errors or variability in the data, and allows for a more precise and reliable analysis.

3. How does the amount of data affect uncertainty?

The amount of data can affect uncertainty in a data set in two ways. With a larger data set, the uncertainty is typically smaller because the sample size is larger. However, if the data is highly variable, a larger data set may not necessarily decrease uncertainty.

4. What are some common sources of uncertainty in data sets?

Some common sources of uncertainty in data sets include measurement errors, sampling errors, and random variation. Other factors such as human error, instrument sensitivity, and environmental factors can also contribute to uncertainty.

5. How can uncertainty in a data set be reduced?

Uncertainty in a data set can be reduced by increasing the sample size, improving measurement techniques, and controlling for external factors that may affect the data. It is also important to properly analyze and interpret the data, taking into account any potential sources of uncertainty.

Similar threads

  • Introductory Physics Homework Help
Replies
20
Views
1K
  • Introductory Physics Homework Help
Replies
9
Views
1K
  • Introductory Physics Homework Help
Replies
6
Views
1K
  • Introductory Physics Homework Help
Replies
5
Views
901
  • Introductory Physics Homework Help
Replies
2
Views
1K
  • Introductory Physics Homework Help
Replies
20
Views
3K
  • Introductory Physics Homework Help
Replies
15
Views
1K
Replies
1
Views
626
  • Introductory Physics Homework Help
Replies
3
Views
3K
  • Introductory Physics Homework Help
Replies
14
Views
1K
Back
Top