Simple Harmonic Motion Question

AI Thread Summary
The discussion centers around a homework problem involving simple harmonic motion, specifically using the equation x = A cos(wt - phi). The user initially calculates time values t1 and t2, assuming a phase angle phi of zero, resulting in an implausible answer of over 40 seconds. Other participants point out that the amplitude (A) is 0.100m and the angular frequency (w) is 1.48 Hz, suggesting that the user's calculations may contain algebraic errors. The conversation emphasizes the need for clarity in the algebraic steps taken to solve for time, indicating that the logic and physical interpretation of the results are critical. The thread highlights the importance of correctly applying the equations and assumptions in simple harmonic motion problems.
FsLiu
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Homework Statement


316m72x.png

Homework Equations



x = A cos(wt-phi)

The Attempt at a Solution



Using the above equation for t, calculating values for t1 at -0.05 and t2 at 0.05, as well as assuming phase angle phi is zero, I get an answer of over 40 seconds.

I think I may be using the wrong equation or perhaps assuming the value of phi incorrectly. Help is appreciated.
 
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What values are you using for that equation (i.e. what A and omega ['w']) ?
 
zhermes said:
What values are you using for that equation (i.e. what A and omega ['w']) ?

Those are both given in the original question, A=0.100m and w=2pi(period inverse) which turns out to be 1.48 Hz
 
I don't see how you could be getting > 40s; can you show us how you solved for t?
 
zhermes said:
I don't see how you could be getting > 40s; can you show us how you solved for t?

Yeah that's the problem, doesn't make sense logically/physically.

I used the equation x = A cos(wt-phi), assumed phi was zero and rearranged for time, t.

Then I did t1 at -0.05m and t2 at +0.05m and then took the difference as the time taken to go from point one to point 2.
 
There must be something wrong with your algebra, could you show your expressions for t
 
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