Hey guys.

How exactly do I do this question???

The rise and fall in sea level due to tides can be modelled by simple harmonic motion. On a certian day, a channel is 10 m deep at 9 am when it is low tide and 16 m deep at 4 pm when it is high tide. if a ship needs 12 m of water to sail down a channel safely, at what times between 9 am and 9 pm can the ship pass through?.