Qualification > Sciences
ALL CIE PHYSICS DOUBTS HERE !!!
ashish:
--- Quote from: Deadly_king on November 12, 2010, 10:59:32 am ---To ashish..........it sure does not exist in practice, but it does on theory. ;D
But each time you make use of a voltmeter in a circuit, you should assume it has infinite resistance so that it draws no current. ;)
--- End quote ---
yeah but i even argued with a teacher saying him that i will believe him only if he shows me an ideal voltmeter
and he smiled at me :D xD
Deadly_king:
--- Quote from: ashish on November 12, 2010, 02:01:39 pm ---yeah but i even argued with a teacher saying him that i will believe him only if he shows me an ideal voltmeter
and he smiled at me :D xD
--- End quote ---
Hahaha..................very smart way to baffle the teacher. :P
thecandydoll:
Oct/Nov 2004. MCQ Q20.
q18
Hypernova:
--- Quote from: thecandydoll on November 13, 2010, 07:02:25 am ---Oct/Nov 2004. MCQ Q20.
q18
--- End quote ---
q18
Your looking for the work done against the 9.0kN force.
Work done by a force = Force x distance moved in the direction of the force
The body has not gained speed, this means that the work done by the 9.0 kN is equal to the work opposing it.
If the body had gained speed, then the work done by the 9.0 kN is greater than the work done opposing by an amount equal to the gain in kinetic energy
the 9.0 kN is equal to the work opposing it.
so the work done by the 9kN is equal to the workdone by friction and by its weight.
Work done by 9kN = Work done by friction + delta Potential energy
9000x40 = Work done by friction + 20000x12
Work done by friction (heat dissipated) = 120000 J
Ans is A
elemis:
+rep Hypernova ;)
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