Solve Harmonic Oscillation Homework: E, F, T, ƒ

[MisterP]

Homework Statement

Harmonically fluctuating object. It`s full energy (E) is 3*10^-5 J. Maximum force (F) on object is 1.5 * 10^-3N. Period is 2 seconds (T) and starting phase (ƒ) is 60°. Need to write equation for these fluctuations.
E = 3*10^-5 J
F= 1.5 * 10^-3N
T = 2 s
ƒ = 60°

Homework Equations

I know this formula X (fluctuation formula) = A*cos(ω*t + ƒ)
ω - fluctuation angular frequency
t - time
ƒ - starting phase

The Attempt at a Solution

I found this formula E/F = A/2. Looks like I can calculate A (max amplitude). So 3*10^-2/1.5 * 10^-3 = A/2 A = 0.04 m (I guess it is in meters?)
So, how can I calculate ω now? Edit: just found ω = 2Π/t, could this be right?

 

[DrClaude]

I found this formula E/F = A/2.

Unless you were told you could use such an equation, my guess is that you need to derive that from more fundamental principles.

A = 0.04 m (I guess it is in meters?)

Don't guess, derive it.

So, how can I calculate ω now? Edit: just found ω = 2Π/t, could this be right?

Do you think this makes sense? What is the definition of the period of oscillation.

 

[BvU]

Hi again P,

You work in a telegraph office ? Such a terse problem statement !

 

[DrClaude]

Hi again P,

You work in a telegraph office ? Such a terse problem statement !

I think that the problem was not originally in English.

By the way, @MisterP, I have changed the title of the thread. These are "oscillations" in English, not "fluctuations."

 

[MisterP]

Seems like a tricky task to me, so I see this so "foggy"
English is not my original language, so its hard to translate such tasks :D :)

 

[MisterP]

Still can`t figure this out..

 

[BvU]

Maximum force (F) on object is 1.5 * 10-3N

At what point in the oscillation period is the restoring force maximum ?

It`s full energy (E) is 3*10-5 J

What is the energy stored in a spring with spring constant $k$ when it is compressed over a distance $x$ ?
What is the expression for the restoring force exercised by a spring with spring constant $k$ when it is compressed over a distance $x$ ?

picture: wikipedia "oscillation" (lemma has no useful formulas for this exercise)