In MATLAB ode45, how do I solve a system of ODE where a parameter is dependent on other parameter, and not time dependant?

Question

Consider the equations for a launch vehicle

dv/dt = T/m - D/m - g*sin(gam)

v*d(gam)/dt = -g(-v^2/W)*cos(gam) where W is a constant

dh/dt = v*sin(gam).

Where v represents velocity, T is thrust.

My thrust values are discrete, hence i have to use interp1, which is straightforward.

However, my drag D ** depends on **velocity itself, how do I incorporate this?

As you can see, a parameter is a function of another parameter.