Math Help Forum - View Single Post

Jhevon · #4 October 10th, 2007, 03:08 PM

Quote:

Originally Posted by steve@thecostins.co.uk

$\omega$ can be calculated with the equation ${\omega} = \frac{2\pi}T$

where $T$ is the period in time for one cycle or oscillation. In the case of the harbour, if working in hours, $T = 12$ , or if working in seconds $T = 12 * 60 * 60$ .

In the question why did they put "If d is the depth of the water above the mean depth"? Why mention of water ABOVE the mean depth?

So then i guess if they're looking for the answer in hours it would be:

$d = 5 \ \cos \frac{1}{2}t$

i still don't see how you got 1/2. if T = 12 then $\frac {2 \pi}{12} = \frac {\pi}6$ (and why did you change to seconds?)

it seems to me, we want to have a formula that calculates the depth of the water when it is above 5m. if that is the case, i think we need more information on what time of the day we are at and what time of the day do we have the max tide