- #1
Sheneron
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Homework Statement
A 0.450 kg object attached to a spring with a force constant of 8.00 N/m vibrates in simple harmonic motion with an amplitude of 11.0 cm.
Calculate the maximum value (magnitude) of its speed and acceleration.[/B]
The Attempt at a Solution
I found both w and t.
[tex] \omega = 4.216[/tex]
[tex] t = 0.145[/tex]
To get t I solved this equation for t.
[tex] x(t) = Acos(\omega t + \phi)[/tex]
[tex]t = \frac{1}{4.216}cos^-1(\frac{x}{11})[/tex]
With that value of t, I solved for v. I got a negative number which is incorrect. However, if at the start I use sine instead of cosine for position i get a different value for t, and get the same answer for v, except positive, which is correct. But why would I use sine for position rather then cosine, and how would I know? Also why would it be positive or negative?