Kinematics[polar coordinate] concept problem

[sunumen]

http://p14.freep.cn/p.aspx?u=v20_p14_p_0711201047589252_0.jpg

Formula:
http://freep.cn/p.aspx?u=v20__p_0711201059233972_0.jpg

1)I need to find out V($$\theta$$). But I remember that r$$\theta$$<dot>
= $$\omega$$ = V($$\theta$$)

Something seems like contradict
Where my concept wrong?
How should I deal with this problem??
I guess that the h should be included ~but why?

 

[rl.bhat]

The car has two velocity components. The horizontal component Vr = r*omega. It is given that h = cos(2theta) + 1. Therefore vertical component of the velocity Vh = dh/dt = -2sin(2theta)*d(theta)/dt.
The resultant of Vr and Vh gives the velocity of the car.

 

[azatkgz]

$$v(\theta)=\omega R(\theta)$$

Distance of car to vertical shift is always changing and equals $$R(\theta)$$

 

[rl.bhat]

This variation is along the radius and hence it does not affect the theta component of the velocity.

 

[azatkgz]

But theta is on x-y plane

$$\omega=\frac{d\theta}{dt}$$

 

[rl.bhat]

Distance of car to vertical shift is always changing and equals Rcos(phy) This velocity does not contribute to V(theta)