A box is hanging from the ceiling by two cables.One forms a 30 degree angle with the ceiling and other forms a 45 degree angle with the ceiling.If the rope that forms the 30 degree angle is measured to have a tension of 1200N.What is the other tensio
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A box is hanging from the ceiling by two cables.One forms a 30 degree angle with the ceiling and other forms a 45 degree angle with the ceiling.If the rope that forms the 30 degree angle is measured to have a tension of 1200N.What is the other tensio
A box is hanging from the ceiling by two cables.One forms a 30 degree angle with the ceiling and other forms a 45 degree angle with the ceiling.If the rope that forms the 30 degree angle is measured to have a tension of 1200N.What is the
other tension of other cables and the mass of the box?
大概是要用:T=MG/cos 30 这个方式~不过还是得不到正确答案~大概是Sin,Cos,Tan那里出问题了~
还有就是,什么是Free Body Diagrams?在这个问题上,Free Body Diagrams在哪里?
好象要用cos 图是对了~但答案好像不对....
A box is hanging from the ceiling by two cables.One forms a 30 degree angle with the ceiling and other forms a 45 degree angle with the ceiling.If the rope that forms the 30 degree angle is measured to have a tension of 1200N.What is the other tensio
30度角的绳子拉力的水平分力：
1200 * cos 60 = 600*sqr（3）N （偷懒不算了）
跟 45度角绳子的拉力 水平分力的大小相同,方向相反.
45度角绳子的拉力：
T2 = 600*sqr（3）/ cos45 = 300 sqrt（6） = 734.84N
重量：mg = T1 * sin30 + T2 * sin 45 = 600 + 600 600*sqr（3） = 1639N
m = 1639/9.8 = 168.3KG
两根绳子的合力等于盒子的重量，就是1200*1/2=600N=60KG，
另外一根绳子的拉力=600/（2^1/2）
收起
30度角的绳子拉力的水平分力：1200*1/2=600N=60KG
跟 45度角绳子的拉力 水平分力的大小相同，方向相反。
45度角绳子的拉力：
600/（2^1/2）=734.84N
重量：mg = T1 * sin30 + T2 * sin 45 = 600 + 600 600*sqr（3） = 1639N
m = 1639/9.8 = 168.3KG