Simple Harmonic Motion of buoy: write eqn describing motion

[joanne1102]

A buoy oscillates in simple harmonic motion. At a given time it is noted that the buoy moves a total of 3.5 feet from its low point to its high point. and that it returns to its high point every 10 seconds. Write an equation that describes the motion of the buoy if it is at its high point at t=0.

I figured amplitude is 1.75, period is pi/5, but is the equation sine or cosine?

1.75 sin pi/5 t or 1.75 cos pi/5 t

 

[skeeter]

Re: Simple Harmonic Motion

period is 10 sec ... \(\displaystyle B = \frac{\pi}{5}\)

high to low to high ... does that describe the shape of a sine or cosine curve?

 

[Deleted member 4993]

Re: Simple Harmonic Motion

A buoy oscillates in simple harmonic motion. At a given time it is noted that the buoy moves a total of 3.5 feet from its low point to its high point. and that it returns to its high point every 10 seconds. Write an equation that describes the motion of the buoy if it is at its high point at t=0.

I figured amplitude is 1.75, period is pi/5, but is the equation sine or cosine?

1.75 sin pi/5 t or 1.75 cos pi/5 t

At t = 0, what is the value of sin(t)? What is the value of cos(0)? What does the problem tell us (initial values)?