1.1. A seagull sits on the surface of the sea and moves up and down as waves pass.

Its height, $h$ metres, above its position in calm water is modelled by the function $h=\frac{1}{2}$sin$(180t)^{\circ}$  where $t$ is the time in seconds after timing commences.

Sketch a graph of $h$ against $t$ for $0\leqt\leq10$ showing the coordinates of the points of intersection with the $t$ axis.

1.2. How many times in the first minute after timing commences is the seagull 0.25 metres above its calm water position?

1.3. Find the time at which the seagull is first 0.25m above its calm water position and moving downwards. Give your answer to 3 significant figures.