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Ask community Community Discussion Question: STATEMENT 1: in pure rolling motion net work done by friction is ZERO
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offline (108)

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STATEMENT 1: in pure rolling motion net work done by friction is ZERO


STATEMENT 2: sum of translational work done by friction and rotaional work done by friction is zero.


answer soon whether A B C or D

    
offline (108)

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any one reply yaar

a big shot is a number of small shots which were kept hitting
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pranav agrawal (1383)

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it is B..... pls rate.......... Mr. hottie.....

ANTI-RAGGING HELPLINE NUMBER ---- 1800-180-5522
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Ankit Kaul (17)

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The answer is B.


That is St1 and St2 are correct and St1 is not a correct explanation of St2.


This Question was asked in the vidyamandir Test Series -3 , this year.

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sti I (224)

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it is b....

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offline (108)

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no the ans given is A .think of it

a big shot is a number of small shots which were kept hitting
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offline (108)

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any one reply.explain why it is B?

a big shot is a number of small shots which were kept hitting
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HEMANT BHARDWAJ (806)

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frinstion acts at lowest point which remain at rest in case of pure rolling and hence work done by it is zero

Beat others otherwise they will beat u
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Abhishek Das (4)

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 here ans. is (b)


at the lowest point , relative motion is zero!! so no friction acts!!

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aagu97 (17)

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ya it should be a


consider a body rolling down an inclined plane


friction acts in upard direction at point of contct


consider only translational motion find work done by f (its negative , as it tries to stop the translational motion0


and work done in ROTATION (its + as friction tries to incr the rotational velocity of the body)


hence net work is 0

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Lalit Kumar (171)

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ans. is A..this was the doubt i had for a long time...actually friction does work for both translation motion...n for the rotational motion if u analyze the plane motion as combination of both....wen u add both the work u will get zero ans...as for one motion it will do + work n for other -ve...u can observe for any rolling body...as their rotational n translational motion r connected by v=wR..the both components of work r of same magnitude n of opposite direction..
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jatin negi (0)

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in rolling motion work done by friction =0  ans-b

there is no slipping of the body in rolling so force of friction acting at the contact point=0

 

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adi (1437)

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how can the wok done by friction be 0

in case of inclined plane  frictional force produces torque which gives rotational kinetic energy to the disc

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AnshikaRathee (257)

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CLEAR EXPLANATION : ans is ( B ) POINTS ARE : 1. net WORK DON BY FRCTION IS ZERO AS POINT OF CONTACT AT REST...KNOWN 2 ALL... 2. NOW ONLY TWO WORKS ARE POSSIBLE...ROTATIONAL AND TRANSLATIONAL...SO THEIR SUM WILL ALSO BE ZERO... 3. BUT THE REASON IS THAT POINT OF CONTACT IS AT REST...
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AnshikaRathee (257)

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RATE PLS...
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AnshikaRathee (257)

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POINT OF CONTACT AT REST MEANS F.D MEIN D=0;
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Anzal Khan (0)

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STATEMENT 1: in pure rolling motion net work done by friction is ZERO
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Anzal Khan (0)

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The answer is clearly a) as the net work done by friction is zero because the translational and rotational work done by friction cancel each other and the point of contact remains at rest only instantaneously..................so the clear answer is a)
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sidharth kamboj (0)

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friction acts tangentially so shouldn't it be F.S equal to zeropls let me know if its correct
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