Work Energy And Power Question 250
Question: A variable force P is maintained tangent to a frictionless cylindrical surface of radius a as shown in figure. By slowly varying this force, a block of weight W is moved and the spring to which it is stretched from position 1 to position 2. The work done by the force P is
Options:
A) $ W a sin \theta $
B) $ \frac{1}{2} ka^{2} {{\theta }^{2}} $
C) $ Wasin \theta + ka^{2}{{\theta }^{2}} $
D) $ Wasin \theta +\frac{1}{2} ka^{2}{{\theta }^{2}} $
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Answer:
Correct Answer: D
Solution:
[d] $ W= mgh +\frac{1}{2}kx^{2} = mg( asin\theta ) +\frac{1}{2} k{{( a\theta )}^{2}} $
$ =Wa\sin \theta +\frac{1}{2}ka^{2}{{\theta }^{2}} $
