Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.

Normal Size Small Size show me how

Normal Size Small Size show me how

# HELUS8CH1

### 8th grade physical science: chapter 1: Motion

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

A ___ is a starting point used to describe the position of an object. | reference point |

The ___ is the direction you must travel from the reference point toward an object. | reference direction |

Units like ___ (m), kilometers (km), and centimeters (cm) are used to describe distances. | meters |

To describe an object’s position, you must include three pieces of information: a reference point, a reference direction, and the distance from the reference point in the ___. | reference direction |

Positive (+)and ___ (-) measurements of distance are often used to describe positions | negative |

___ measurements are usually in the reference direction, or toward the object from the reference point. | Positive |

Negative measurements are usually in the opposite direction from the reference direction.Negative measurements are usually in the ___ direction from the reference direction.They start from the reference point and measure away from the object | opposite |

One way to describe the position of an object is as an ___ pointing from a reference point toward the object | arrow |

A ___ is a quantity that has both a size and a direction | vector |

Vectors are often drawn as ___ pointing away from a reference point in the referencedirection. | arrows |

___ is one example of a vector. | Position |

The length of a position vector is the ___ from the reference point to the object whose position the vector represents | distance |

Maps have two ___, east-west and north-south. | reference directions |

A two-dimensional map can be drawn as a graph used to represent the location of objects with two ___ | reference directions |

East is usually on the positive ___, and north is usually on the positive ___. | x-axis. y-axis |

A location must be chosen to be the reference point, or ___, of the graph. | origin |

___ is the difference between the initial position and the final position of an object. | Displacement |

Displacement is measured as a distance from a reference point in a particular direction, and so displacement is a ___. | vector |

A ___ measures the change in one quantity in a particular length of time | rate |

___ is the rate of change of position over a period of time | Speed |

An object that moves at a ____ travels the same distance each and every second | constant speed |

___, or the speed of an object at a specific instant of time, is especially useful to measure for objects whose speed changes. | Instantaneous speed |

An object’s ___ is its total distance traveled divided by the total time it traveled | average speed |

The equation for average speed is average speed = total distance divided by ____. | total time |

If you know any two quantities in the average speed equation, you can use the equation to calculate the ___. | third |

The unit for speed is a ___ unit divided by a time unit. The SI unit for speed is ___ | distance, m/s |

___ is a measurement of both the speed and direction of motion of an object | Velocity |

Velocity is a ___. It has both a size (the speed of the object) and a direction (the direction the object is moving) | vector |

Speed is different from ___ because speed does not include the direction in which the object is moving | velocity |

___, another vector, is the rate at which velocity changes over time | Acceleration |

When an object speeds up, the direction of its ___ is the same as the direction of its motion. | acceleration |

When an object ___, its acceleration is in the opposite direction from the direction of its motion | slows down |

When an object changes the direction in which it is moving, its velocity changes. This means that it is ___ | accelerating |

On a position-time graph, ___ is usually plotted on the y-axis and time is usually plotted on the ___. | position, x-axis |

The ___ of a line is the steepness of the line. | slope |

On a position-time graph, an object’s speed can be determined by looking at the ___ of the line that represents that object’s motion. | slope |

On a position-time graph, the steeper the slope of a line, the ___ the object was moving. | faster |

On a position-time graph, the flatter the slope of the line, the ___ the object was moving | slower |

The vertical change, or change along the y-axis, on a graph as an object moves between two points is sometimes called the ___. | rise |

The horizontal change, or change along the x-axis, on a graph as an object moves betweentwo points is sometimes called the ___ | run |

The ___ of a line can be calculated by dividing the rise between two points on the line by the run between the same two points | slope |

Only objects moving at ___ speeds have straight line position-time graphs | constant |

The average speed of the entire trip of an object that does not move at constant speed can be calculated by finding the slope between the ___ and ___ data points on the graph of the object’s motion. | starting, ending |

If a ___ graph has a horizontal line, the object whose speed the graph represents was moving at a constant speed. | speed-time |

If an object speeds up, its line on a speed-time graph curves up to the right. The steeper the slope, the faster its speed is ___. | increasing |

When an object ___, its line on a speed-time graph slopes down to the right | slows down |

Created by:
jnosik