- #1

songoku

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- 325

- Homework Statement
- Please see the picture below

- Relevant Equations
- Simple harmonic motion

Equation for the tide:

$$y=-\cos \left(\frac{2 \pi}{6}t\right)+2$$

When ##y## = 1.5 m :

$$1.5=-\cos \left(\frac{2 \pi}{6}t\right)+2$$

$$-0.5=-\cos \left(\frac{\pi}{3}t\right)$$

$$\frac{\pi}{3}=\frac{\pi}{3}t$$

$$t=1$$

But the answer key is t = 2. Where is my mistake?

Thanks