System Dynamics and Control problem - finding the block diagram from given equations

[super sky]

I'm having a little trouble using the Latex thing so I've only used it for some of the equations.

Homework Statement

Elevation control of a tracking antenna.
Equation of motion for the system J$$\theta$$$$^{..}$$+B$$\theta$$$$^{.}$$ = T_c+w ... Equation 1 (those dots are meant to be above the thetas, but I don't know how to do that... see attachment q1 for the equation)
Antenna and drive mechanism have J = moment of inertia, B is the damping coefficient, T_c is the torque from the drive motor, w is a disturbance torque, and $$\theta$$ is elevation angle of the dish.

Model the dish as a thin disc with diameter 2m, mass 40kg and rotates about central axis (J=MR²/4)
Damping coefficient = 20Nmsec

Torque exerted by DC motor: T_m=K_T/R_aVa-K_TK_B/R_a$$\theta$$_m$$^{.}$$ ... equation 2
where $$\theta$$_m is the angular position of the motor shaft which is connected to the load, via a 50:1 gearbox.

Motor parameters J_m=0.01kgm², R_a=5ohms, K_T=0.2Nm/A, K_B=2Vsec

a) Draw a block diagram of the motor itself(i.e. showing the relationship between the applied voltave V_a, the load torque T_c and motor speed $$\theta$$_m$$^{.}$$ and position $$\theta$$_m)

b) Find the transfer function between the applied voltage V_a and the antenna angle theta assuming zero disturbance torque.

c) Suppose the applied voltage is computed so that theta tracks a reference command theta_r according to the feedback law V_A=K(theta_r-theta) where K is the feedback gain. Draw a block diagram of the resulting feedback system showing both theta, the reference position theta_r and disturbance torque w. Find the transfer function between theta_r and theta assuming zero disturbance torque.

There are a few other parts to the question, but they need to be worked through sequentially and I'm a little more hopeful about having an idea of them once I know what to do here.

Homework Equations

Laplace Transforms... The derivative one: Laplace{\ddot{f}}=s²F(s)-sf(0)-s\dot{f}(0)

Transfer function of a closed loop system T(s) = G(s)/(1+G(s)H(s))

The Attempt at a Solution

Taking equation 1 and laplace transforming, assuming zero initial conditions:
Js²theta(s) + Bstheta(s) = T_c(s) +w

Rearrange:
theta(s) = 1/(Js²+Bs) * (T_c(s) +w)

See attachment 1, after where I've written equations 1 and 2...
I think I'm going ok up to where I try to draw the block diagram with T_m in attachment 2.
Then I'm not sure what to do with the equation to make it into a block diagram. I don't think it's a closed loop (because that comes later in part c with the reference..?) but I seem to have two inputs, V_a and theta_m... And so I'm not sure how to go about putting it in a block diagram other than what I've done.

Any help would be super. Thanks.