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Two blocks A and B of same masses are resting in equilibrium on an inclined plane having inclination with horizontal =alpha(gt0). The blocks are touching and exerting no zero normal force on each other with block B higher than A. Coeffcient of static friction of A with incline =1.2 adn of B=0.8. If motons not imminent |
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Answer» `alphagt30^(@)` `f_(A)=mg SIN alpha +N` `f_(B)=mg sin alpha-N` To SHOW `N!=0` `f_(b_("max"))=0.8mgcosalpha` `=N=mg[sinalpha-0.8cosalpha]` `N=mg sec alpha [tan alpha-0.8]` `N=mgsec alpha [tan alpha-0.8]` For `alpha gt tan^(-1) (0.8)` `f_(A)gt f_(B)` for `alpha ge tan^(-1)(0.8)f_(A)=f_(B)` 
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