- #1
channel1
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i need a review. why does lifting a book at a constant speed result in a constant KE but changing PE? obviously KE = 1/2 mv^2 but I am looking for a conceptual answer. doesn't KE need to equal PE for energy to be conserved?
im in e&m right now and there's a statement in my book saying that the book situation is analogous to potential within an emf source. so W = 0 (work done on a test charge within an ideal emf source), U is increased, and KE is constant. but in the book analogy doesn't the book have to be moving in the +/- x direction for W = 0?
so to summarize i have two questions, (1) concerns how energy is conserved with a constant KE but changing U and (2) concerns how W = 0 if there is a changing U
please answer both questions in terms of the book analogy AND the emf source! thanks in advance :)
im in e&m right now and there's a statement in my book saying that the book situation is analogous to potential within an emf source. so W = 0 (work done on a test charge within an ideal emf source), U is increased, and KE is constant. but in the book analogy doesn't the book have to be moving in the +/- x direction for W = 0?
so to summarize i have two questions, (1) concerns how energy is conserved with a constant KE but changing U and (2) concerns how W = 0 if there is a changing U
please answer both questions in terms of the book analogy AND the emf source! thanks in advance :)