How Do You Calculate the Oscillation Frequency of a Compressed Rubber Pad?

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Barrowlands
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So, I'm trying to brush up on my undergrad physics, and I'm sure this is a bone-headed question, so please bear with me.

Homework Statement


A heavy object, when placed on a rubber pad that is to be used as a shock absorber, compresses the pad by 1cm. If the object is given a vertical tap, it will oscillate. Ignoring the damping, estimate the oscillation frequency. [The book I'm using actually gives the solution]

Homework Equations


x(t)=A*sin(sqrt(k/m)t+[itex]\phi[/itex])
ω=sqrt(k/m)
F=k|l-l0|

The Attempt at a Solution


We'll call x0 the equilibrium displacement, x0=1cm
k=spring constant of rubber
so
k(l-l0)=k*x0=mg (equilibrium)
gives us
k=(mg)/(x0)
then
ω=sqrt(k/m)
which eventually solves to
ω=sqrt(g/x0)

The book gives an answer of sqrt(980) rad/s. My question is given the units from ω=sqrt(g/x0) (meters, seconds, centimeters), how do they arrive at radians?
 
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X0 is 0.01 m. So the unit of sqrt(g/x0) is 1/s.
ω is the angular frequency, it is measured in radians/second, but radian is dimensionless. ω=2πf (f=frequency).

ehild
 
Makes sense. I actually just beefed the algebra cancelling my units. Thanks!