The discussion revolves around the work done in lifting and lowering an object, specifically focusing on the kinetic and potential energy changes during the process. Participants explore the mechanics of lifting a book from one shelf to another, addressing concepts of work, energy transfer, and the forces involved in different phases of motion.
Participants do not reach a consensus, as there are multiple competing views regarding the relationship between work done, kinetic energy, and the forces involved in lifting and lowering the object. The discussion remains unresolved with differing interpretations of the energy dynamics.
Some participants highlight the need for clearer definitions of terms and quantities used in the discussion. There are also unresolved questions regarding the assumptions made about the motion phases and the relationships between work and energy.
If the object is moving upward and slowing down, the lifting force is less than ##mg##.Lnewqban said:The lifting force is whatever force is necessary to overcome gravity, it can't be less.
What's a "momentary push"? It has to last for some length of time, and during that time the object moves a distance ##d##.rudransh verma said:But there is a confusion here in W=Fd , d is the distance up to which the force is applied and up to which the body travels. It’s not a momentary push.
Oh! It’s the same thing.Mister T said:What's a "momentary push"? It has to last for some length of time, and during that time the object moves a distance ##d##.
When using high forces for very short distance mean momentary push. In my book resnik they are not using this thing but constant force throughout the motion and displacement. Even though after a set time both will produce same change in energy.Ibix said:You can use a very high force for a very short distance and throw the book on to the shelf. Or you can use a force barely stronger than the weight and lift the book smoothly. Either way, the work done by the force is the same.
If the book starts and stops, they cannot be using constant force.rudransh verma said:In my book resnik they are not using this thing but constant force throughout the motion and displacement.