337U=12ky2
Or, U ∞ y2
So, U1U2=y1y2 whole ^2
So,
20U2=6-06-3 whole ^2
=> U2=5
Ans: 5 joules.
If 20 Joules of work is done in compressing a spring from 0 cm to 6 cm then find the work done in compressing the same from 3 cm to 6 cm.
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7 Answers
269sir...is the answer 10 joules.....????
- Astha Gupta is it 0.8 joules....?????Upvote·0· Reply ·2013-06-04 23:18:41
Sayantan Hazra still not correct :(- Sukrit Roy Chowdhury 6.1J ?
- Sayantan Hazra Nope!! still incorrect!!
Arey, follow the hint....... :)
206show all the steps plz....and this is not the correct answer... :(
337206Since U is dependent only on position, so U changes at every y......this directly implies that y ≠difference in positions.......
- Sayan Sinha So what is the correct answer?
206Hint:
From Work-energy theorem,
U = 12kx2
or, U2 - U1 = 12kx22 - 12kx12
Use this to obtain the answer :)
206From W.E Theorem,
Work done = Change in KE
or, Work done = Change in PE (since PE + KE for any system = constant)
or, W = U2 - U1
For given case, W = 20 J; x1 = 0 cm ; x2 = 6 cm ;
Thus, we get W = U2 - U1
or, 20 = 12kx22 - 12kx12
Solve for k........
Now use the value of k by putting x1 = 3 cm ; x2 = 6 cm ;
in the same equation to find W......and you are done!! :)