# Angular motion

1. Dec 9, 2004

### sarahowen

we are just about to take a test in physis.. im quite scared. i have revised on all the topics required but i dont get the use of omega in angular velocity equations. what is the equation and when do i need to use it?
sarah

2. Dec 9, 2004

### futb0l

well - u can take ur normal kinematics equation and replace v with omega.
like....

$$\theta = \theta_0 + \omega t + \alpha t$$

alpha is the angular acceleration.

3. Dec 9, 2004

### briton

Just learn

v=rw

w= 2.pi.f = 2.pi / T

f = 1/T =w / 2.pi

a = v^2/r = rw^2

F=mv^2/r = mrw^2

4. Dec 9, 2004

### prasanna

Replace v by $$\omega$$

a by $$\alpha$$

and x by $$\theta$$

in your kinematics equations to get the rotational equations!

$$\omega = \omega_0 + \alpha t$$
$$\theta = \theta_0 + \omega_0 t + \frac{1}{2}\alpha t^2$$
$$\omega^2 = \omega_0^2 + 2\alpha\theta$$

And the Equations posted by Briton are also very important

Last edited: Dec 9, 2004