The discussion centers on the work-energy principle as it applies to lifting and lowering an object, specifically a book. It establishes that the work done by the applied force (W_a) and the work done by gravity (W_g) are equal in magnitude but opposite in direction during uniform motion. The kinetic energy (K) of the book transitions from zero to a non-zero value and back to zero as it is lifted, demonstrating the conversion of kinetic energy to potential energy. The net work done on the book is zero, indicating that energy is conserved throughout the process.
PREREQUISITESStudents of physics, educators teaching mechanics, and anyone interested in understanding the principles of work and energy in physical systems.
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.