Suppose the force is resolved parallel to the arms AB and AC of the frame. The magnitude of the resolved component along the arm AC is xN. The value of x, to the nearest integer, is . [Given : sin(35 ) = 0.573, cos(35 ) = 0.819 sin(110 ) = 0.939, cos(110 ) = 0.342 JView written solutionFree
Correct answer: 82
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Interpret the geometry
The force of magnitude acts vertically downward at point .
It is to be resolved along the two non-perpendicular arms and .
From the given trigonometric values, the included geometry is consistent with:
- arm making with the vertical,
- arm making with the horizontal on the other side, so the angle between the two arms is
Hence, when resolving a force along two non-orthogonal directions, we use the triangle/law of sines method.
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Let the resolved components be
- along :
- along :
Their vector sum equals the applied force .
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Use the law of sines for resolution along two inclined directions
If a force is resolved along two directions with included angle , and the angle between and one arm is , then the angle between and the other arm is also
For oblique resolution:
Therefore,
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Substitute the given values
So,
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Nearest integer
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Compare with stored answer
Stored correct answer = .
My derived answer is , which does not match .
The likely reason is that the actual figure may have a different placement of the angle than inferred from the text alone. If instead the component along is opposite the angle in the force triangle, one would get which can produce a value near depending on the exact figure. However, from the standard oblique resolution with the most natural interpretation of the supplied angles, the result is .
Therefore I disagree with the stored answer based on the information visible in the prompt alone.
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