Circular Functions Application

Question Is:

It is suggested that the height h(t) meters of the tide above mean sea level on 1st january at Warnung is given approximately by the rule h(t) = 4sin(pi/6t), where t is the number of hours after midnight.

A) when was high tide?

B) what was the height of the tide?

C) what was the height of the tide at 8 am?

D) a boat can only cross the harbour bar when the tide is atleast 1 meter above mean sea level. when could the boat cross the harbour bar on 1st january?

please i need help with this