Second-Order Harmonic Motion Equation: Solve as 2 linear diff eqs

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Homework Help Overview

The problem involves converting a second-order differential equation for a harmonic oscillator, specifically \( y'' + \omega^2 y = 0 \), into a system of two linear ordinary differential equations. The original poster also seeks the analytic solution given specific initial conditions.

Discussion Character

  • Exploratory, Problem interpretation, Assumption checking

Approaches and Questions Raised

  • Participants discuss the transformation of the second-order ODE into a system of first-order equations, suggesting definitions for new variables to represent the derivatives. There is also a question about the meaning of "ICs" or initial conditions, indicating some confusion about terminology.

Discussion Status

The discussion is ongoing, with some participants providing suggestions for transforming the equation and clarifying terms. There is a mix of humor and confusion regarding terminology, but no consensus has been reached on the best approach to the problem.

Contextual Notes

There is mention of the original poster's struggle with the problem and a reference to the need for Python coding, which may imply constraints related to the homework assignment. The initial conditions provided are specific but not fully explored in the discussion.

leonmate
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Homework Statement



[/B]
Write the second-order equation for the harmonic oscillator,

y ̈ + ω2y = 0

as two linear ordinary differential equations. What is the analytic solution y(t) if ω = 2π, y(0) = 1 and y′(0) = 0?


Homework Equations

The Attempt at a Solution



So, I have to write some python code to solve this and a series of other questions but I'm falling at the first hundle! :(

What does it mean, as two linear ordinary differential equations, how do you do that? I've been searching the internet for hours and I can't find what I'm looking for. I watched about an hour of khan academy second-order equations.

Could someone help me out, I can do the coding I just don't know what to put in!
 
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How about these ODEs?
u = y
v = y'
so that v' = y"
Then
u' = v
v' = - w^2 u
And similarly transform the ICs.
 
ICs?
 
leonmate said:
ICs?
IC = initial conditions
 
leonmate said:

Homework Statement



[/B]
Write the second-order equation for the harmonic oscillator,

y ̈ + ω2y = 0

as two linear ordinary differential equations. What is the analytic solution y(t) if ω = 2π, y(0) = 1 and y′(0) = 0?

Homework Equations

The Attempt at a Solution



So, I have to write some python code to solve this and a series of other questions but I'm falling at the first hundle! :(

What does it mean, as two linear ordinary differential equations, how do you do that? I've been searching the internet for hours and I can't find what I'm looking for. I watched about an hour of khan academy second-order equations.

Could someone help me out, I can do the coding I just don't know what to put in!

I'm not sure what a 'hundle' is, but it sounds serious.

In any event, the OP asks you to find the analytic solution to the DE, which you should be able to do without writing any Python code.

It's not clear why you had so much difficulty with converting a second order ODE to a system of first-order equations. The standard methods of solving ODEs numerically (Euler, Runge-Kutta, etc.) are all based on solving first order equations only, thus a higher order equation must first be transformed into a system of first-order equations before a numerical solution can be obtained:

http://www.efunda.com/math/num_ode/num_ode.cfm
 
SteamKing said:
I'm not sure what a 'hundle' is, but it sounds serious.

I understand OP made a typo ,but the above line is seriously funny :p.
 

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