Glossary
- accuracy
- the degree to which a measured value agrees with correct value for that measurement
- approximation
- an estimated value based on prior experience and reasoning
- classical physics
- physics that was developed from the Renaissance to the end of the nineteenth century
- conversion factor
- a ratio expressing how many of one unit are equal to another unit
- derived units
- units that can be calculated using algebraic combinations of the fundamental units
- English units
- system of measurement used in the United States; includes units of measurement such as feet, gallons, and pounds
- fundamental units
- units that can only be expressed relative to the procedure used to measure them
- kilogram
- the SI unit for mass, kg
- law
- a description, using concise language or a mathematical formula, a generalized pattern in nature that is supported by scientific evidence and repeated experiments
- meter
- the SI unit for length, m
- method of adding percents
- the percent uncertainty in a quantity calculated by multiplication or division is the sum of the percent uncertainties in the items used to make the calculation
- metric system
- a system in which values can be calculated in factors of 10
- model
- representation of something that is often too difficult or impossible to display directly
- modern physics
- the study of relativity, quantum mechanics, or both
- order of magnitude
- refers to the size of a quantity as it relates to a power of 10
- percent uncertainty
- the ratio of the uncertainty of a measurement to the measured value, expressed as a percentage
- physical quantity
- a characteristic or property of an object that can be measured or calculated from other measurements
- physics
- the science concerned with describing the interactions of energy, matter, space, and time; it is especially interested in what fundamental mechanisms underlie every phenomenon
- precision
- the degree to which repeated measurements agree with each other
- quantum mechanics
- the study of objects smaller than can be seen with a microscope
- relativity
- the study of objects moving at speeds greater than about 1 percent of the speed of light, or of objects being affected by a strong gravitational field
- scientific method
- a method that typically begins with an observation and question that the scientist will research; next, the scientist typically performs some research about the topic and then devises a hypothesis; then, the scientist will test the hypothesis by performing an experiment; finally, the scientist analyzes the results of the experiment and draws a conclusion
- second
- the SI unit for time, s
- SI units
- the international system of units that scientists in most countries have agreed to use; includes units such as meters, liters, and grams
- significant figures
- express the precision of a measuring tool used to measure a value
- theory
- an explanation for patterns in nature that is supported by scientific evidence and verified multiple times by various groups of researchers
- uncertainty
- a quantitative measure of how much your measured values deviate from a standard or expected value
- units
- a standard used for expressing and comparing measurements