Uncertainty - Addition and Subtraction

TL;DR

This lesson explains how to perform calculations involving uncertainty for addition and subtraction of measured values.

Transcript

in this lesson we're going to talk about calculations associated with uncertainty specifically addition and subtraction so let's start with this example let's say we have 43.3 plus or minus 0.2 let's say the units are inches and we're going to add that to 35.6 plus or minus 0.3 inches so what we have here is our measured value and our estimated unc... Read More

Key Insights

• 🪜 Adding uncertainties involves simply adding their values to each other.
• ❓ The uncertainty of the final result is greater than the individual uncertainties, regardless of the operation.
• 🪜 Subtraction does not involve subtracting the uncertainties; they should still be added.

Questions & Answers

Q: How do you perform calculations with uncertainty for addition?

When adding measured values, simply add their respective uncertainties together. The final result will have a combined uncertainty.

Q: What should be done when subtracting values with uncertainty?

Despite the subtraction, the uncertainty values should still be added. This is because the uncertainties compound with mathematical operations.

Q: Why is the uncertainty of the final result greater than the individual uncertainties?

The uncertainty compounds with mathematical operations, resulting in a larger uncertainty for the final result. This accounts for the range of potential values.

Q: Can the uncertainty be greater than the measured value?

Yes, it is possible for the uncertainty to be greater than the measured value. This situation arises when the range of potential values is larger than the measured value itself.

Summary & Key Takeaways

• Adding or subtracting measured values involves adding their respective uncertainties to each other.

• The uncertainty of the final result is always greater than the individual uncertainties.

• When subtracting values, the uncertainty values should still be added, not subtracted.