Question

20. Miguel is driving his motorboat across a river. The speed of the boat in still water is 11 mi/h. The river flows directly south at 2 mi/h. If Miguel heads directly west, what are the boat’s resultant speed and direction?

Answer 1

make your sketch to get a right-angled triangle with sides 11 and 2.

The hypotenuse will be your resultant:
r^2 = 2^2 + 11^2 = 125
r = √125 = 5√3 or appr 11.18 mph

tanØ = 2/11
Ø = 10.3°

so it have a bearing of W 10.3° S