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Grade 12General Physics

A 8 kg block is at rest on a horizontal floor. If you push horizontally on the 8 kg block with a force of 20 N, it just starts to move.

(a) What is the coefficient of static friction?

(b) A 10.0 kg block is stacked on top of the 8 kg block. What is the magnitude F of the force, acting horizontally on the 8 kg block as before, that is required to make the two blocks start to move?

Profile image of sachin  singh
15 Years agoGrade 12
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1 Answer

Profile image of vikas askiitian expert
ApprovedApproved Tutor Answer15 Years ago

ans a)if the block just starts moving then static friction force is equal to the applied force

  friction force=F (applied force)

    u.N =20    (here N is normal reaction =mg=80N)

     u=20/80=.25

ans b) F(min)=static friction force

                   =u.N             (N=mg =180N)

                   =0.25*180=45N