有哪位大哥大姐会这些物理问题吗？(修改了）

kitwei1219

1.)Determine the minimum P to ensure the block is in verge to move up.Given the coefficient of static,μ = 0.2.
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(Ans=7330.6N)

2.)The block with the mass of 100kg located on an inclined plane as shown in figure.If B is in the equilibrium determine whether the block is balance or not.Determine the friction force between the block and contact surface and determine the direction of friction force.Given the coefficient of static is 0.3 and the coefficient of kinetic is 0.2.
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(Ans:F=184.4N)

谢谢！

射即是空

对不起，太迟看到你的贴了，希望还来得及。


Fx=0
=> Pcos30+981cos20-9810sin30-Fs=0

Since Fs=0.2*(9810cos30-981sin20-Psin30)

=> Pcos30+981cos20-9810sin30-0.2*(9810cos30-981sin20-Psin30)=0

P=7330.6N





392.4/sin30 - 981sin20 - 150 = 299.3N
=>Not balance

Fs=981cos20*0.2=184.4N