Find a model for simple harmonic motion if the position at t=0 is 2, the amplitude is 2 cm, and the period seconds.

Question

anonymous · Answer

Actually you can use either sin or cos. It will only change your starting value. I would suggest using cos since at t =0 the position is at its highest amplitude which is how the cos function starts. (BTW in your original post, you left out the period value.)

avanti · Answer

oops the period is 6. there is only one correct answer so im not sure which to go with.

anonymous · Answer

Well, actually, there can be many correct answers with periodic functions but for the one you described. One is:
$$y=2\cos(\frac{ \pi }{ 3 }t)$$
Another would be:
$$y=2\sin(\frac{ \pi }{ 3 }t +\frac{ \pi }{ 2 })$$
There are actually an infinite number of correct equations, but the two most common would be the two above. I find the first one to be the more elegant of the two.