Skills Flashcards
What does the prefix tera signify?
10^12
What does the prefix giga signify?
10^9
What does the prefix mega signify?
10^6
What does the prefix kilo signify?
10^3
What does the prefix milli signify?
10^-3
What does the prefix micro signify?
10^-6
What does the prefix nano signify?
10^-9
What does the prefix pico signify?
10^-12
What is absolute uncertainty?
The actual amount by which the quantity is uncertain
What is percentage uncertainty?
Absolute uncertainty divided by the mean quantity given as a percentage
What is accurate data?
Data that close to the true value
What is precise data?
Data that has little variation from the mean
What is repeatable data?
Data where the same experimenter gets the same results with the same equipment and method
What is reproducible data?
Data where a different experimenter gets the same result with the same method
What is resolution?
Smallest change in a quantity that can be measured by a measuring instrument
What are the uses of graphs?
- Extrapolating data that could not be gathered
- Estimating unknown quantities
- Identifying anomalies
- Identifying trends
What is an order of magnitude estimate?
An estimate which is in the same power of 10 as the real value
What are the 7 SI units?
Mass - kg
Length - m
Time - s
Temperature - K
Amount of substance - mol
Current - A
Luminous intensity - Cd (candela)
What are random errors?
Unpredictable variation between measurements that leads to a spread of values about the true value
How could random errors be reduced?
- Taking at least 3 repeats and then a mean
- Use computers or data loggers to reduce human error and enable smaller intervals
- Use appropriate equipment with a high resolution
What are systematic errors?
Error that causes readings to differ from the true value by a fixed amount
How could systematic errors be reduced?
- Calibrate apparatus by measuring a known value to easily identify systematic errors
- Taring digital meters before use
- Read measurements at eye level to avoid parallax error
