Frequency and angular frequency of sinusoidal vibrations in s.h.m.

[Bugsy23]

Homework Statement

I need to calculate the frequency, angular frequency and period of sinusoidal vibrations in simple harmonic motion. The acceleration amplitude is 10g (98.1m s^-2) and the vibration amplitude is 2cm

Homework Equations

The equation I have for frequency is
f=(√(a/A))/2*pi
where a is the acceleration amplitude and A is the vibration amplitude
And the angular frequency equation is
$$\omega$$=2*pi*f

The Attempt at a Solution

for the frequency I got
f=√(98.1ms^-2/2x10^-2m)=70/2*pi=11Hz
which seems quite plausible, but when I then try to calculate angular frequency I get
$$\omega$$=2pi*11=69s^-1
which seems too large a number, since all the examples I have seen have angular frequencies of between about 0 and 3s^-1. Is this actually right or have I gone wrong somewhere?

 

[housemartin]

I think you got the answer right. if you think its large, look at acceleration, it's quite large too, and displacement amplitude is small...

 

[The CdePster]

Just in addition, I think you can also use the equation a=-ang freq^2 * max displacement. Its much faster, however you get an answer of 70s^-1 for the angular frequency. Which is more accurate i do not know. Somebody'll probably tell me I am wrong now. :)