## IB Physics Glossary

Browse the glossary using this index

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

## U |
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## Ultrasound A-scan is an amplitude-modulated scan with information represented as a graph of signal strength against time. | |

## Ultrasound B-scan is a brightness-modulated scan with information represented as levels of brightness. | |

## Uncertainties • resulting from measurements are combined under the following rules: addition/subtraction of quantities => add absolute errors If multiplication/division of quantities = add relative/fractional/percentage errors If and If raising quantity to n'th power = multiply relative/fractional/percentage error by n If | |

## Unified atomic mass unit (u)is 1/12 ^{th} the mass of a neutral carbon-12 atom. | |

## Uniform acceleration occurs when the acceleration Since acceleration is a vector quantity, constant implies a uniform magnitude and direction for the acceleration. The equations of uniform acceleration are where u is the initial velocity, v is the final velocity after time t, a is the acceleration and s is the displacement. | |