The discussion revolves around the concept of uniform circular motion, particularly whether an object, such as a pencil, spun in a vacuum would continue to spin indefinitely. Participants explore the implications of centripetal acceleration, the role of forces, and the conservation of angular momentum in the absence of external influences.
Participants generally agree that in a vacuum, a pencil spun initially would continue to spin without external forces acting on it. However, there are competing views regarding the necessity of forces for maintaining circular motion and the implications of angular momentum, indicating that the discussion remains unresolved on these points.
The discussion includes various assumptions about the nature of forces, energy, and motion, particularly regarding the definitions of circular motion and the role of internal versus external forces. There are also references to Newton's laws and the concept of angular momentum, which may require further clarification for complete understanding.
sophiecentaur said:Whatever forces are acting, no energy is 'consumed' or transferred if there is no movement in the direction of those forces (i.e. the string / pencil gets no longer or shorter). Work done is Force times Distance moved in the direction of the force.
ViolentCorpse said:The distance covered is circular, so isn't there even some component of distance being covered in the direction of the centripetal force?