click below

click below

Normal Size Small Size show me how

# Phys 02 Motion

### Linear Motion (Speed, Acceleration, Motion Graphs) Terms

Question | Answer |
---|---|

physics term for your 'surroundings' | frame of reference |

reference point (0,0) in a coordinate system | origin |

meaning of "at rest" | motionless |

location within the frame of reference | position |

change in position with respect to surroundings (frame of reference) | motion |

when your motion can be different depending on what it is compared to, that is _?_ motion | relative |

when riding on an elevator, you are motionless compared to _?_ | the inside of the elevator |

when riding on an elevator, you are moving relative to _?_ | the floors in the building, etc. |

when treating an object as a single point in motion, you are using the _?_ model | particle |

describe the motion: .............. | slower steady speed |

describe the motion: . . . . . . . . | faster steady speed |

describe the motion: . . . . . . . | very fast steady motion |

describe the motion: .. . . . . . . . | accelerating |

separation between positions | distance |

distance in a particular direction | displacement |

abbreviation for distance/displacement | ∆x |

quantity having only magnitude (size) | scalar |

quantity having BOTH magnitude (size) and direction | vector |

total distance ÷ total time | average speed |

rate of change of distance (or "how fast") | speed |

quantity measured with a speedometer | instantaneous speed |

device in car that measures total distance traveled | odometer |

rate of change of displacement (speed in a particular direction) | velocity |

examples include +25 m/s, or 15 m/s East | velocity |

SI unit of distance or displacement | m |

SI unit of speed or velocity | m/s |

direction assigned to negative (–) horizontal displacement or velocity | west |

direction assigned to positive (+) horizontal displacement or velocity | east |

symbol for speed or velocity | v |

SI unit for time | s |

rate of change of speed/velocity | acceleration |

SI unit of acceleration | m/s^2 (m/s/s) |

another term for negative (–) acceleration... but don't use it in physics! | deceleration |

abbreviation for acceleration | a |

abbreviation for acceleration due to gravity | g |

gravitational acceleration near Earth's surface (3 significant digits) | 9.80 m/s^2 |

graph shape that indicates y is independent of x | horizontal line |

graph shape that indicates y is directly proportional to x | linear (diagonal) line |

graph shape that indicates y is inversely proportional to x | hyperbolic |

graph shape that indicates y is proportional to the square of x | parabolic |

x-t graph for object at rest | horizontal line (may be on or above the x-axis) |

v-t graph for object at rest | horizontal line on the x-axis (0) |

a-t graph for object at rest | horizontal line on the x-axis (0) |

x-t graph for object at constant speed/velocity | linear (diagonal) line |

v-t graph for object at constant speed/velocity | horizontal line (above x-axis) |

a-t graph for object at constant speed/velocity | horizontal line on the x-axis (0) |

x-t graph for object undergoing constant acceleration | parabola |

v-t graph for object undergoing constant acceleration | linear (diagonal) line |

a-t graph for object undergoing constant acceleration | horizontal line (above x-axis if +, below x-axis if –) |

synonym for "constant" or "unchanging" used to describe motion | uniform |

slope of an x-t graph: unit and quantity given | m/s; speed |

slope of a v-t graph: unit and quantity given | m/s^2; acceleration |

slope of an a-t graph: unit and quantity given | m/s^3; the 'jerk' |

area underneath an x-t graph: unit and quantity given | m•s; --- |

area underneath a v-t graph: unit and quantity given | m; distance |

area underneath an a-t graph: unit and quantity given | m/s; (change in) speed |

if graph lines A & B on an x-t graph cross at point P, what does that represent? | A & B are at the same place (ex: A passes B at point P) |

if graph lines A & B on a v-t graph cross at point P, what does that represent? | A & B are moving at the same speed at P (not passing!!!) |

if the motion of A and B are on the same x-t graph, how do you know which is going faster? | the faster one has a steeper graph |

if the motion of A and B are on the same a-t graph, how do you know which has the greatest change in speed? | the one with greater change will have a larger area between its graph |