Question
Two fixed frictionless inclined planes making an angle 30° and 60° with the vertical are shown in the figure. Two blocks A and B are placed on the two planes. What is the relative vertical acceleration of A with respect to B?
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4.9 ms-2 in horizontal direction
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9.8 ms-2 in vertical direction
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zero
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4.9 ms-2 in vertical direction
Solution
D.
4.9 ms-2 in vertical direction
For the motion of block along inclined plane
mg sin θ =ma
a = g sin θ
where a is along the inclined plane.
The vertical component of acceleration is g sin2θ
Therefore, the relative vertical acceleration of A with respect to B is
g (sin260 - sin230) = g/2 = 4.9 ms-2 (in vertical direction)
