syms x(t) y(t) v(t) m c g s=symengine disp ('1)------------------------------------------') cond1=x(0)==0; cond2=diff(x,t)==0; conds=[cond1 cond2] dx=diff(x,t); dx2=diff(x,t,2); dv=diff(v,t); dx2=diff(x,t,2); ode=m*diff(v,t)+c*v==m*g
Sol=solve(ode,conds,dx,x)

 Réponse acceptée

Ameer Hamza
Ameer Hamza le 2 Juin 2018

0 votes

You can access the fields of a struct using dot notation. For example
Sol.c
Sol.g
Also, since you are trying to solve a differential equation, use dsolve(),
Sol=dsolve(ode,conds)

8 commentaires

madhan ravi
madhan ravi le 2 Juin 2018
but still I cannot find the result I wanted :/
madhan ravi
madhan ravi le 2 Juin 2018
madhan ravi
madhan ravi le 2 Juin 2018
Ameer Hamza
Ameer Hamza le 2 Juin 2018
It is not clear which differential equation you are trying to solve. Can you clearly specify the required equations.
madhan ravi
madhan ravi le 2 Juin 2018
Modifié(e) : madhan ravi le 2 Juin 2018
I want to solve m(dx.^2/dt.^2)+c(dx/dt)=m*g; where m = mass, c=air resistance , g=acceleration due to gravity , x=distance travelled , x(0)=0, dx/dt(0)=0.
You can solve this equation as follow
syms x(t) m c g
disp ('1)------------------------------------------')
dx = diff(x);
cond1=x(0)==0;
cond2=dx(0)==0;
conds=[cond1 cond2];
ode = m*diff(x,2) + c*diff(x) == m*g;
Sol=dsolve(ode,conds)
Sol =
(g*m*t)/c - (g*m^2)/c^2 + (g*m^2*exp(-(c*t)/m))/c^2
madhan ravi
madhan ravi le 2 Juin 2018
Thank you so much you are great
Ameer Hamza
Ameer Hamza le 2 Juin 2018
You are welcome.

Connectez-vous pour commenter.

Catégories

En savoir plus sur Symbolic Math Toolbox dans Centre d'aide et File Exchange

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by