一物体受到水平方向和与水平方向成60°角的两个力作用,已知两个力的大小均为2,求它的合力的大小及方向 光滑水平桌面上有一个物体,质量是2kg,受到互成120°角的...
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\u4e24\u5206\u529b\u7b49\u5927\u4e14\u4e92\u6210120\u00b0\u5939\u89d2\uff0c\u5219\u7531\u5e73\u884c\u56db\u8fb9\u5f62\u5b9a\u5219\uff0c\u5408\u529b\u4e0e\u5206\u529b\u7b49\u5927\uff0cF=10N\uff0cF=ma\uff0c\u89e3\u5f97\uff1aa=Fm\uff1d102m/s2\uff1d5m/s2\uff0e\u52a0\u901f\u5ea6\u65b9\u5411\u4e0eF\u76f8\u540c\uff0c\u5373\u4e24\u5206\u529b\u7684\u89d2\u5e73\u5206\u7ebf\u65b9\u5411\uff0e\u7b54\uff1a\u8fd9\u4e2a\u7269\u4f53\u7684\u52a0\u901f\u5ea6\u4e3a5m/s2\uff0e
60°夹角的力分解为垂直方向的力:2×sin60°=根号3N,水平方向力=2×cos60°=1N所以水平方向的合力=3N,垂直方向的力=根号3N=1.73N
合力大小为直角三角形的斜边长=根号12 N=3.46N
sina=根号3÷根号12=1/2,则a=30°
所以,合力大小为3.46N
方向:与水平方向夹角30°。
合力大小为F=2*60*cos30=60根号3N86方向与水平成30度角gko
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