How do you do significant figures.
How dobyou do dimensional analysis
http://www.chemteam.info/SigFigs/SigFigRules.html
https://www.chem.tamu.edu/class/fyp/mathrev/mr-da.html
To apply significant figures, follow these steps:
1. Determine the number of significant figures in a given measurement:
- Non-zero digits are always significant (e.g. 1, 2, 3, 4, 5, 6, 7, 8, 9).
- Any zeros between non-zero digits are significant (e.g. 2003 has four significant figures).
- Leading zeros (zeros before any non-zero digit) are not significant (e.g. 0.045 has two significant figures).
- Trailing zeros (zeros after the last non-zero digit) are sometimes significant (e.g. 450 has two significant figures, but 450.0 has four significant figures).
2. Perform calculations involving significant figures:
- Addition and subtraction: The result should be rounded to the same decimal place as the measurement with the least decimal places.
- Multiplication and division: The result should have the same number of significant figures as the measurement with the fewest significant figures.
Regarding dimensional analysis:
1. Understand the concept of units: Units are used to measure physical quantities. Each physical quantity has a specific unit associated with it (e.g. length is measured in meters, mass in grams, time in seconds).
2. Set up conversion factors: Conversion factors are ratios that relate different units of the same physical quantity. They allow you to convert from one unit to another. For example, 1 meter is equal to 100 centimeters, so the conversion factor would be 1 m / 100 cm.
3. Use cancellation: Dimensional analysis works by canceling out the units you don't want, while keeping the desired units. Start with the given measurement, multiply it by conversion factors that cancel out unwanted units, and ensure the desired units remain.
4. Check for proper units and dimensional consistency: At the end of the calculation, check whether the resulting units are as expected. If they are not, review the conversion factors and calculations to ensure dimensional consistency and correct units.
Remember, dimensional analysis allows you to convert between units and helps maintain consistency in calculations.