Virtual works

1. Jan 11, 2012

chimay

The request is to calcutate the acceleration o the body 1.Making referement to the figure, I have to ignore the spring at first.
My solution is:
$$a_1=g[2m_1+2m_2-4m_4sin(p)]/(2m_1+3m_2+4m_3+12m_4)$$
that cames from:
$$m_1gdx+m_2gdx-m_4gsin(p)(2dx)=m_1a+((3/2)m_2R_2^2/4R_2^2)4adx+(1/2)m_3R_3^2/R_3^2(4adx)+(3/2)m_4R_4^2/(R_4^2)(4adx)$$
since $$dx_2=dx_3=dx_4=2dx_1$$

The "right" result is:
$$a_1=g[4m1+4m2-8m4sin(p)]/(4m1+3m2+4m3+12m4)$$

I think that my error lies in the calculum of the equivalent masses! :( Can someone help me?

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Last edited: Jan 11, 2012