PREGUNTAEl movimiento de un sistema masa - resorte con amortiguación está regido por la ecuación diferencial : d2xdt2 + bdxdt + 25x = 0.
La ecuación del movimiento subamortiguado b = 6 y la ecuación del movimiento críticamente amortiguado b = 10, en función del tiempo respectivamente son :
Seleccione dos :
1.
X(t) = C1e−4tcos3t + C2e−4tsen3t
2.
X(t) = C1e5t + C2te5
3.
X(t) = C1e−3tcos4t + C2e−3tsen4t
4.
X(t) = C1e−5t + C2te−5t
SOLUCIÓN
Hola!
Resolvemos la ecuación diferencial
Para b = 6 <img src="https://tex.z-dn.net/?f=%5Cdfrac%7Bd%5E%7B2%7Dx%7D%7Bdt%5E%7B2%7D%7D%20%2B%20b%5Cdfrac%7Bdx%7D%7Bdt%7D%20%2B%2025x%20%3D%200%20%5C%5C%5C%5C%5Cdfrac%7Bd%5E%7B2%7Dx%7D%7Bdt%5E%7B2%7D%7D%20%2B%206%5Cdfrac%7Bdx%7D%7Bdt%7D%20%2B%2025x%20%3D%200%20%5C%5C%5C%5CAsumimos%5C%3A%20que%20%5C%3A%20la%20%5C%3A%20soluci%5C%27on%20%5C%3A%20tiene%20%5C%3A%20la%20%5C%3Aforma%5C%5C%5C%5C%5Cboldsymbol%7Bx%20%3D%20e%5E%7B%5Clambda%20x%7D%7D%5C%5C%5C%5CEntonces%5C%5C%5C%5C%5Cboldsymbol%7B%2A%7D%20x%27%20%3D%20%5Clambda%20e%5E%7B%5Clambda%20x%7D%5C%5C%5C%5C%5Cboldsymbol%7B%2A%7D%20x%27%27%20%3D%20%5Clambda%5E%7B2%7D%20e%5E%7B%5Clambda%20x%7D" /> <img src="https://tex.z-dn.net/?f=Reemplazamos%20%5C%3A%20en%20%5C%3Ala%20%5C%3A%20E.D.%5C%5C%5C%5Cx%27%27%20%2B%206x%27%2B25x%20%3D%200%5C%5C%5C%5C%5Clambda%5E%7B2%7D%20e%5E%7B%5Clambda%20x%7D%2B6%5Clambda%20e%5E%7B%5Clambda%20x%7D%20%2B%2025e%5E%7B%5Clambda%20x%7D%20%3D%200%5C%5C%5C%5C%5Cunderbrace%7Be%5E%7B%5Clambda%20x%7D%7D_%7B%5Cneq%200%7D%5Cunderbrace%7B%28%5Clambda%5E%7B2%7D%2B6%5Clambda%20%2B25%29%7D_%7B%3D0%7D%20%3D%200%5C%5C%5C%5C%5C%5C%5Clambda%5E%7B2%7D%2B6%5Clambda%20%2B25%20%3D0%5C%5C%5C%5CResolviendo%5C%5C%5C%5C%5Clambda_%7B1%7D%20%3D%20-3%20-%204i%5C%5C%5C%5C%5Clambda_%7B2%7D%20%3D%20-3%20%2B4i%5C%5C%5C%5CLa%20%5C%3A%20ecuaci%5C%27on%20%5C%3Ageneral%20%5C%3A%20es%5C%5C%5C%5C%5Cboxed%7B%5Cboldsymbol%7B%5Cmathrm%7Bx%20%3D%20C_%7B1%7De%5E%7B-3t%7D%5Csin%284t%29%2BC_%7B2%7De%5E%7B-3t%7D%5Ccos%284t%29%7D%7D%7D" />
Para b = 10 <img src="https://tex.z-dn.net/?f=%5Cdfrac%7Bd%5E%7B2%7Dx%7D%7Bdt%5E%7B2%7D%7D%20%2B%20b%5Cdfrac%7Bdx%7D%7Bdt%7D%20%2B%2025x%20%3D%200%20%5C%5C%5C%5C%5Cdfrac%7Bd%5E%7B2%7Dx%7D%7Bdt%5E%7B2%7D%7D%20%2B%2010%5Cdfrac%7Bdx%7D%7Bdt%7D%20%2B%2025x%20%3D%200%20%5C%5C%5C%5CAsumimos%5C%3A%20que%20%5C%3A%20la%20%5C%3A%20soluci%5C%27on%20%5C%3A%20tiene%20%5C%3A%20la%20%5C%3Aforma%5C%5C%5C%5C%5Cboldsymbol%7Bx%20%3D%20e%5E%7B%5Clambda%20x%7D%7D%5C%5C%5C%5CEntonces%5C%5C%5C%5C%5Cboldsymbol%7B%2A%7D%20x%27%20%3D%20%5Clambda%20e%5E%7B%5Clambda%20x%7D%5C%5C%5C%5C%5Cboldsymbol%7B%2A%7D%20x%27%27%20%3D%20%5Clambda%5E%7B2%7D%20e%5E%7B%5Clambda%20x%7D" /> <img src="https://tex.z-dn.net/?f=Reemplazamos%20%5C%3A%20en%20%5C%3Ala%20%5C%3A%20E.D.%5C%5C%5C%5Cx%27%27%20%2B%2010x%27%2B25x%20%3D%200%5C%5C%5C%5C%5Clambda%5E%7B2%7D%20e%5E%7B%5Clambda%20x%7D%2B10%5Clambda%20e%5E%7B%5Clambda%20x%7D%20%2B%2025e%5E%7B%5Clambda%20x%7D%20%3D%200%5C%5C%5C%5C%5Cunderbrace%7Be%5E%7B%5Clambda%20x%7D%7D_%7B%5Cneq%200%7D%5Cunderbrace%7B%28%5Clambda%5E%7B2%7D%2B10%5Clambda%20%2B25%29%7D_%7B%3D0%7D%20%3D%200%5C%5C%5C%5C%5C%5C%5Clambda%5E%7B2%7D%2B10%5Clambda%20%2B25%20%3D0%5C%5C%5C%5CResolviendo%5C%5C%5C%5C%5Clambda_%7B1%7D%20%3D-5%5C%5C%5C%5C%5Clambda_%7B2%7D%20%3D%20-5%5C%5C%5C%5CLa%20%5C%3A%20ecuaci%5C%27on%20%5C%3Ageneral%20%5C%3A%20es%5C%5C%5C%5C%5Cboxed%7B%5Cboldsymbol%7B%5Cmathrm%7Bx%20%3D%20C_%7B1%7De%5E%7B-5t%7D%2BC_%7B2%7Dxe%5E%7B-5t%7D%7D%7D%7D" />
Rpta.
Seleccionaremos la opción 3.
Y 4. respectivamente.