Recent content by uber_kim

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    Lagrangian equation for 5 pulley Atwood Machine.

    Homework Statement Consider the Atwood’s pulley shown below. The masses are 4m, 3m, and m. Let x and y be the directed distances from the centers of the fixed (i.e. inertial) top pulleys for the left and right masses as indicated. http://imgur.com/VXEygxt a) Write down the Lagrangian...
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    Need some help with differential equations for mechanics.

    Homework Statement I'm having problems with some differential equations, just need to know where I'm going wrong. Homework Equations The Attempt at a Solution a) mv\stackrel{dv}{dx}=F(x) mvdv=F(x)dx m∫vdv=∫F(x)dx v^2=vv^{2}_{0}+\stackrel{2}{m}∫F(x)dx...
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    Solving a First Order Differential Equation with Initial Conditions.

    Homework Statement Solve the initial value problem: t(dy/dt)+8y=t^3 where t>0 and y(1)=0 Homework Equations None? The Attempt at a Solution It's a linear equation, so rearranged to dy/dt+8y/t=t^2. Took the integrating factor e^(∫8/tdt)=t^8 and multiplied through...
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    Interval of convergence.

    Homework Statement Find the radius and the interval of convergence for the series: Ʃ((-1)nxn)/(4nlnn) with sum n=2 to ∞. Homework Equations The Attempt at a Solution I'm testing for the left and right side of the interval. I've found that cn=1/(lnn), an=1/4, and R=1. I used...
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    A general convergent series under different circumstances.

    Homework Statement Ʃan (sum from n=1 to ∞) converges. 1) Determine whether the series Ʃln(1+an) (sum from n=1 to ∞) converges or diverges. Assume that an>0 for all n. 2) Show each of the following statements or give a counter-example that establishes that it is false: a)Ʃai2 (sum i=1...
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    Testing for series convergence.

    Homework Statement \sum(\frac{2n}{2n+1})n2 (The sum being from n=1 to ∞). Homework Equations The Attempt at a Solution Used exponent properties to get (\frac{2n}{2n+1})2n. Using the root test, the nth root of an = lim n->∞(\frac{2n}{2n+1})2 = 1. However, the root test is...
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