Physics
(i) Derive a relationship between S.I. and C.G.S. unit of work.
(ii) A force acts on a body and displaces it by a distance S in a direction at an angle θ with the direction of force. What should be the value of θ to get the maximum positive work?
Work, Energy & Power
ICSE 2018
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Answer
S.I. unit of work is joule and C.G.S. unit of work is erg.
Since, work = Force x displacement
1 joule = 1 newton x 1 metre
= 105 dyne x 100 cm
= 107 dyne x cm
= 107 erg
1 joule = 107 erg
(ii) Work W = F.S. cos θ
For maximum work, cos θ = 1 or θ = 0°
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