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Grade 12Mechanics

Ques) A block of mass m is paled at rest on a horizontal rough surface with the angle of friction @. The block is pulled with a force F at an angle theta with the horizontal.Show that the mmin value of F required to move the block is [mgsin@ ] / cos( theta - @).

Profile image of Tushar  Watts
16 Years agoGrade 12
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1 Answer

Profile image of Ramesh V
16 Years ago

here represent theta by x

frictional coeff. = tan @

on balancing forces :

in X-dirn :                             F cosx = f

where f = N.tan@

in Y-dirn.:                          Fsinx + N = mg

on solving, we get

F(cosx - tan@.sinx ) = mg.tan@

F = mg.sin@ / cos(x - @ )

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