The discussion revolves around the concepts of rotation and translation as they apply to the motion of a beam (or board) pivoting at a hinge, specifically in the context of an elbow joint. Participants explore whether the motion can be classified as both rotational and translational when the string holding the beam is cut.
Participants generally agree that the motion involves both rotation and translation, but there is some debate regarding the definitions and implications of translation in this scenario. The discussion remains unresolved regarding the strict classification of the motion.
Limitations include varying interpretations of translation, dependence on the definitions of motion types, and the need for specific conditions to achieve pure rotation.
So even though the beam will be tracing a large circle around the hinge (or more likely swinging back and forth) we can call this translation? My reasoning was because the center of mass of the board is moving as it swings. Is that correct?.Scott said:
The Centre of Mass of the board would drop and move to the left so that would be looked upon as translation. To avoid this, you would need to (appropriately) raise the elbow joint and move it to the right. Then you would have only rotation.Scott said:
Even though not all movement vectors of the object are moving in space by the same amount in a given direction, we can still call this translation?sophiecentaur said:
Why not? The translation doesn't need to be in a straight line or in a chosen direction. We are talking in terms of translation of the CM.physics gal said:
Yes, you can decompose the same motion into rotation and translation in different ways.physics gal said: