+244 An helicopter flies in a strange pattern, all at the same altitude of 5 km: 1) it flies 29 km in a direction 30.0° east of north, 2) it flies 20 km due south, and 3) it flies 10 km in a direction 30.0° north of west. How far did the helicopter end up from its starting point?
A.59.0 km
B.11.7 km
C.18.8 km
D.23.0 km
E.5.0 km
+129852 Here's my approach to this one
Let him start at(0,0)......first, he flies to the point given by: (29cos 60, 29sin60) = (14.5, 25.1)
Then ....he flies 20 km directly south and ends up at (14.5, 5.1)
Then......he flies to the point given by (14.5 + 10 cos150, 5.1 + 10 sin150) = (5.83975, 10.1)
The distance from this point to the origin [ where he started] =
sqrt [ 5.83975^2 + 10.1^2] ≈ 11.67 km ≈ 11.7 km
[ Just as Melody said.....!!!! ]
+118677 Hi Chris,
My logic wasn't that complicated.
I did a rough sketch on a peice of paper and realised there was a 90, 60, 30 degree triangle there.
The hypotenuse is 20 and one side is 10 so the other is 10sqrt3.
So the distance from the beginning is 29-10sqrt3 = 11.7 km
Here is a more precise diagram.
