Runge Kutta for solving 2nd order ODE

In summary, we introduced a new variable v=tw' and solved the resulting first order differential system to find the solution for (wh(1), vh(1)) = (0.995, -0.0998) at t=1/10.
  • #1
hsong9
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1

Homework Statement


(tw')' + tw = 0 with w(0) = 1, w'(0) = 0 on the interval [0,1]
by introducing the new variable v=tw' and considering the resulting first order differential system involving w and v
Report your computed solution (wh(1),vh(1)) for h=1/10.

Homework Equations





The Attempt at a Solution


x'(t) = f(x,t),
x(t0) = x0
I have no idea how I apply v'=tw into above formulas.
Could anyone show me one step?
 
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  • #2


Hello there,

I can help you with this problem. To introduce the new variable v=tw', we can rewrite the original equation as:

v' + w = 0

Now, we can consider the resulting first order differential system involving w and v:

w' = v/t
v' = -w

We can solve this system using the initial conditions w(0) = 1 and v(0) = 0. The solution for w(t) is:

w(t) = cos(t)

And the solution for v(t) is:

v(t) = -sin(t)

Now, to find the values of w and v at t=1/10, we can substitute t=1/10 into the above equations:

w(1/10) = cos(1/10) = 0.995
v(1/10) = -sin(1/10) = -0.0998

Therefore, the solution for (wh(1), vh(1)) is (0.995, -0.0998).

I hope this helps! Let me know if you have any further questions.
 

1. What is Runge Kutta method for solving 2nd order ODE?

Runge Kutta method is a numerical approach used to approximate the solutions of second-order ordinary differential equations (ODEs). It is a widely used algorithm that involves solving a series of equations to estimate the next value of the solution.

2. How does Runge Kutta method work?

Runge Kutta method works by breaking down the second-order ODE into a system of two first-order ODEs. It then uses a set of equations to iteratively calculate the values of the solution at different points, with each iteration providing a more accurate approximation.

3. What are the advantages of using Runge Kutta method?

Runge Kutta method is a versatile and efficient numerical method for solving ODEs. It can handle a wide range of problems, including stiff equations and systems with multiple equations. It also provides more accurate results compared to other numerical methods.

4. Are there any limitations to using Runge Kutta method?

One limitation of Runge Kutta method is that it requires the ODE to be written in first-order form. It also requires a fixed step size, which can lead to errors if the step size is not chosen carefully. Additionally, it can be computationally expensive for systems with many equations.

5. When should I use Runge Kutta method for solving 2nd order ODEs?

Runge Kutta method is a good choice for solving 2nd order ODEs when analytical solutions are not available or are difficult to obtain. It is also useful for problems that cannot be solved using other numerical methods, such as Euler's method. However, for simple ODEs, other methods may be more efficient.

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