Centripetal Acceleration circular disk

[Simple Echo]

Homework Statement

A circular disk of radius 30 cm is rotating with an angular acceleration of 1 radian/ s2. What is the tangential acceleration of a point on the rim of the disk? What is its centripetal acceleration if the angular speed is 3 rev / s?

Homework Equations

tangential acceleration = angular acceleration * radius

The Attempt at a Solution

tangential acceleration = 1 * 30 = 30 cm/sec^2

I'm not even sure I got that part right, my online reading just throws a bunch of random variables at me, and I have no idea what they're referring to. If someone could just explain the equation to me to figure out the Centripetal Acceleration, that would be great. I'm not asking you to do it, I just want to know how. I already failed at this question.

 

[rock.freak667]

What formula did you use for centripetal acceleration?

 

[Simple Echo]

What formula did you use for centripetal acceleration?

That's one of my problems, I have no idea what the formula is to use.

 

[Simple Echo]

ac = v^2/r

So
Centripetal Acceleration = 3^2/30?
0.3 rev/s

I don't even think this is the right equation

 

[rock.freak667]

ac = v^2/r

So
Centripetal Acceleration = 3^2/30?
0.3 rev/s

I don't even think this is the right equation

$$a_c=\frac{v^2}{r}$$

but remember that v=rw so substitute that to get another form of centripetal acceleration.

 

[Simple Echo]

Velocity = Radius * W
What is the variable w?

 

[rock.freak667]

Velocity = Radius * W
What is the variable w?

angular velocity