Translational phenomena are common in life, such as cars moving in a straight line on the road, windows or drawers sliding, and bullets firing quickly after being fired from the barrel of a firearm, and. then there is the train moving forward on the track. These are actually typical translation movements.
And the phenomenon of rotation, like using awrenchto tighten a screw, and a rotating windmill to extract screw water, there are wind turbinestop The rotational movement of wind blades and the continuous rotation of clock hands are all typical rotational phenomena.
Translation means that all parts of an object move to another place in a certain direction, and the distance traveled is the same, which is called translation. Rotation is the continuous circular movement of an object around acertain point or axis.
Basic properties of translation
(1) The shape and size of graphics before and after translation do not change, only the position changes.
(2) Once the graph is translated, the line segments connecting the corresponding points are parallel (or on the same straight line) and equal.
(3) Several consecutive translations are equivalent to a single translation.
(4) The number after an even number of symmetries is equal to the number after translation.
(5) Translation is determined by direction and distance.
(6) After translation, the corresponding line segments are parallel (or collinear) and equal, the corresponding angles are equal, and the line segments connected to the corresponding points are parallel (or collinear) and equal.
Basic properties of rotation
(1) The distance between the corresponding point and the center of rotation is equal.
(2) The angle between the point corresponding and the line segment connected to the center of rotation is equal to the angle of rotation.
(3) The graphs before and after the rotation are congruent, that is, the size and shape of the graphs before and after the rotation have not changed.
(4) The center of rotation is the only point that does not move.
(5) The angle cut by the line connecting a set of corresponding points is equal to the angle of rotation.