foundations of physics

• The SI unit of force is the newton (N).
• the prefix pico(p) is 1x10-12
• en error is the difference between the result obtained and the true value of the quantity.
• scalar quantities have magnitude but not direction
• vector quantities have both magnitude and direction
• an SI unit is a base unit of a physical quantity
• accuracy is a measure of how close a measured value is to the true, accepted value
• a measurement is valid if it measures what it is supposed to be measuring
• random error is an error that occurs due to unexpected changes during an experiment that cant be predicted
• an anomaly is a value in a set of results that does not fit the trend of the data
• a systematic error is an error that occurs due to faulty equipment or faults in the experimental method
• one way to reduce systematic error is to zero the balance when its empty
• one way to reduce random error is to repeat the experiment and calculate a mean
• precision is how close together the readings are
• an experiment is repeatable if the original experimenter can redo the experiment with the same equipment and method and get the same results
• to find the percentage uncertainty, divide the uncertainty by the measured value then multiply it by 100%
• percentage uncertainty tells us how accurate our measurement was
• the uncertainty on a measurement is calculated by adding up all the sources of errors
• if the experiment can be redone by a different person or with a different technique and equipment and the same results are found, it is reproducible
• resolution is the smallest change in the quantity being measured that gives a recognisable change in reading