Calculating Frequency of Oscillating Mass on a Spring

[aleferesco]

Homework Statement

The position of a mass oscillating on a spring is given by x(t) = (18.3cm)cos[(2.35s^-1)t] .
What is the frequency of this motion?

Homework Equations

X= Amplitude x Cos (2pi/T x time)

The Attempt at a Solution

I know that frequency= 1/Period, I am trying to use f= 1/(2.35s^-1) but it doesn't seem correct. Also I've tried multiplying the amplitude by 2... f= 1/(18.3cm)x2


Thanks

 

[Rake-MC]

so the form is $$x(t) = Acos( \omega t )$$

where $$\omega = 2 \pi f$$

Can you see how this helps you?

 

[aleferesco]

so omega= 2.35s^-1

and so to find frequency I could just do f=2.35s^-1/2pi

I'm not sure about the reversing 1/1/T = s^-1

 

[Rake-MC]

[...]

I'm not sure about the reversing 1/1/T = s^-1

Sorry I don't understand what you're saying here, but yes:

$$f = \frac{\omega}{2\pi}$$

are you confused because omega is a reciprocal? That should play no part in exchanging frequency with period. So just follow that formula and you should be fine.

Note: I have not solved the problem numerically, but I can tell it's going to be a very small answer.

 

[aleferesco]

Thank you very much!