Question #b93f4

1 Answer
Mar 28, 2017

(1) 100 N


Let the reactionary force exerted by each of the two fixed wall AB and AC on two ends of the rod (perpendicular to the plane of the walls) be #R# N.

The line of action of each of these two forces will be inclined with the vertical line passing through the CG of the rod at an angle #60^@#

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So the vertical component of each reactionary force will be #Rcos60^@# and the total force of reaction (upward) will be #=2Rcos60^@=2Rxx1/2=R# N.

This total force of reaction will be just equal and opposite to the weight of the rod of mass 10kg.
So #R=10kgxxg=10kgxx10m"/"s^2=100N#

Hence the option (1) is the answer.