1At the end the potential energy is converted into kinetic energy 1/2mv2.......as energy is always conserved!!!!!!!
One end of a carpet is nailed to an inclined wedge. Carpet starts to open by rolling purely on the inclined plane. As the time passes potential energy decreases and increase in kinetic energy results. Where does this energy go in the end!!
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10 Answers
11Actually see when the carpet was lift up at that point of height from ground (where the K.E and P.E are both zero),the K.E goes on decreasing and the P.E goes on increasing......
After reaching that height P.E is max. and K.E is zero.......
Now while coming down the P.E goes on decreasing and K.E is increasing...........................................
Again at last the carpet comes to rest and there the K.E and P.E becomes zero.................................
I hope u can understand.................
1Carpet is opening on the inclined plane. Finally the center of mass of carpet is not at ground level it is somewhere at the mid of the inclined plane.
Moreover I didnt get the part where you said at the highest point total energy is not zero (as PE is max and KE =0 ) but on the ground total energy comes out to be zero, so where does the energy go?. why does the loss in PE not comes out to be equal to gain in KE.
I hope u can understand..............
71I don't that when the carpet opens up completely, at that moment the COM of the carpet is at rest too.
It must have got some instantaneous velocity, which will certainly be overpowered since the carpet is not free to slide and hence lost to work.
1even if all surfaces r frictionless....kinetic energy increases due to obv reason (acc due to gravity)....now the mass of the rolling object (the carpet) is not constant coz as the carpet rolls, it leaves behind some part of it....
the part wich is left behind comes to rest....hence...the energy in the carpet is distributed into the rolling part n the rest part...gradually the carpet opens up fully n all the energy is converted to potential
i guess that shud be the the reason...is it??
1n isnt it that the conservation of energy law applies only wen mass is constant??...for physical objects??.. (unless they r travelling at the speed of light of course)
1I think if the surfaces are smooth then the carpet will not open...... :)
1@abhishek
i had the same doubt....bt the problem clearly mentions that one end of the carpet is nailed....
so...even if the surface is smooth....the carpet will undergo pure rolling coz the part already opened will provide the necessary friction!!!