Where bearings are given, they are in degrees East of North (so North is 000, degrees,000∘, East is 090, degrees,090∘, South is 180, degrees,180∘and West 270, degrees,270 ∘). For the purposes of this exercise, assume the Earth is flat. a) In which direction would I have to travel in order to travel North (relative to a stationary observer) if I am swimming in a river with a current running 0, point, 40, m, s, to the power minus 1 ,0.40ms −1 to the East, and I can swim at 1, point, 5, m, s, to the power minus 1 ,1.5ms −1 relative to the water? Give your answer as a bearing (degrees clockwise from North) to 3 significant figures.

b) In which direction would I have to travel in order to travel North (relative to a stationary observer) if I am flying in a 15, k, m, h, to the power minus 1 ,15kmh −1 wind coming from the West and can fly at 90, k, m, h, to the power minus 1 ,90kmh −1 relative to the air? Give your answer as a bearing (degrees clockwise from North) to 3 significant figures.

c) How fast do I move Northwards over the ground in part (b)?