Question

Conservation of energy says that ∆Etotal= (Etotal)f−(Etotal)i= 0, so we would expect a slope of zero, as well, since the slope of a straight line is ∆y/∆x which, in our case, would be ∆E/∆x. Why isn’t the slope for the graph of Etotal vs.|∆x| zero? Does this mean energy isn’t conserved? Explain what’s going on here. HINT: what does it mean for a system to be “isolated” and what is the effect of using your “hands” in dragging the block to new initial displacements?Think about what’s changing.

Answer 1

Here when we go through the Conservation of energy theorem then we do says that ∆Etotal= (Etotal)f−(Etotal)i= 0,

Because here the energy is conserved at our point of refrence taken , as for example we we displaces certain object with mass and applied force then,

Here first the static frictional energy is overcome by applied work done force then only object will move and then it will gain some kinetic energy but as there is no any external forces are acting here so that the net energy of the system will be conserved at each point in the system but here this is the total energy of the system and when draw the slope by taking two reference point then we will have energy at that two reference point and other points also so we cannot say here that slope will be zero.