## Comment on Key Terms from Glossary

Special | A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z |

**ALL**

## A |
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## accuracythe degree to which a measured value agrees with correct value for that measurement | |

## approximationan estimated value based on prior experience and reasoning | |

## C |
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## classical physicsphysics that was developed from the Renaissance to the end of the 19th century | |

## conversion factora ratio expressing how many of one unit are equal to another unit | |

## D |
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## derived unitsunits that can be calculated using algebraic combinations of the fundamental units | |

## E |
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## English unitssystem of measurement used in the United States; includes units of measurement such as feet, gallons, and pounds | |

## F |
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## fundamental unitsunits that can only be expressed relative to the procedure used to measure them | |

## K |
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## kilogramthe SI unit for mass, abbreviated (kg) | |

## L |
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## lawa description, using concise language or a mathematical formula, a generalized pattern in nature that is supported by scientific evidence and repeated experiments | |

## M |
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## meterthe SI unit for length, abbreviated (m) | |

## method of adding percentsthe 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 systema system in which values can be calculated in factors of 10 | |

## modelrepresentation of something that is often too difficult (or impossible) to display directly | |

## modern physicsthe study of relativity, quantum mechanics, or both | |

## O |
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## order of magnituderefers to the size of a quantity as it relates to a power of 10 | |

## P |
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## percent uncertaintythe ratio of the uncertainty of a measurement to the measured value, expressed as a percentage | |

## physical quantitya characteristic or property of an object that can be measured or calculated from other measurements | |

## physicsthe science concerned with describing the interactions of energy, matter, space, and time; it is especially interested in what fundamental mechanisms underlie every phenomenon | |

## precisionthe degree to which repeated measurements agree with each other | |

## Q |
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## quantum mechanicsthe study of objects smaller than can be seen with a microscope | |

## R |
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## relativitythe study of objects moving at speeds greater than about 1% of the speed of light, or of objects being affected by a strong gravitational field | |

## S |
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## secondthe SI unit for time, abbreviated (s) | |

## SI units | |

## significant figuresexpress the precision of a measuring tool used to measure a value | |

## T |
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## theoryan explanation for patterns in nature that is supported by scientific evidence and verified multiple times by various groups of researchers | |

## U |
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## uncertaintya quantitative measure of how much your measured values deviate from a standard or expected value | |

## unitsa standard used for expressing and comparing measurements | |