Percentage uncertainty
Percentage uncertainty basically tells us ‘what percentage of the measurement could we be off by?’
For example, if we have a measurement of 10cm \pm 1cm, that means we could be
off by 1cm. To find the percentage uncertainty, we can use the formula:
\text{percentage uncertainty} = \left(\frac{\text{absolute uncertainty}}{\text{measurement}}\right) \times 100\%
For example, to find the percentage uncertainty of our absolute uncertainty
example above (5.25cm \pm 0.15cm):
\text{percentage uncertainty} = \left(\frac{0.15cm}{5.25cm}\right) \times 100\% \approx 2.86\%
| Question | Answer |
|---|
| What is percentage uncertainty? | It tells us what percentage of the measurement we could be off by. |
| What is the formula for percentage uncertainty? | \text{percentage uncertainty} = \left(\frac{\text{absolute uncertainty}}{\text{measurement}}\right) \times 100\% |
| How do you calculate the percentage uncertainty for a measurement of 10cm \pm 1cm? | \left(\frac{1cm}{10cm}\right) \times 100\% = 10\% |
| What is the percentage uncertainty of 5.25cm \pm 0.15cm? | \left(\frac{0.15cm}{5.25cm}\right) \times 100\% \approx 2.86\% |