3 A boat can travel at a speed of \(2 \mathrm {~ms} ^ { - 1 }\) in still water. The boat is to cross a river in which a current flows at a speed of \(0.8 \mathrm {~m} \mathrm {~s} ^ { - 1 }\). The angle between the direction in which the boat is pointing and the bank is \(\alpha\). The boat travels so that the resultant velocity of the boat is perpendicular to the bank.
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1. Show that \(\alpha = 66.4 ^ { \circ }\) correct to three significant figures.
2. 1. Find the magnitude of the resultant velocity of the boat.
   2. The width of the river is 14 metres. Find the time that it takes for the boat to cross the river.