# Thread: Physics help w/ Trig

1. ## Physics help w/ Trig

Hey guys, im having a problem with one oy my physics problems that involves trigonometry, among other things. Any help or guidance would be great.

Path A is 6.0 km long heading 60.0° north of east. Path B is 6.0 km long in a direction due east. Path C is 3.0 km long heading 315° counterclockwise from east.

(a) Graphically add the hiker's displacements in the order A, B, C.
Magnitude of displacement _________ km
Direction of displacement ___________ ° (counterclockwise from east)

(b) Graphically add the hiker's displacements in the order C, B, A.
Magnitude of displacement _________ km
Direction of displacement ___________ ° (counterclockwise from east)

2. Set up a coordinate axis with the positive y-axis being north and the positive x-axis being east. Place your first path (vector) at the origin. If the hiker hikes on it, how far will she go in the x direction? How far will she go in the y direction?

You don't necessarily have to know trigonometry to do this problem, since all of the angles used in this problem are 'special' angles. Instead of using trig, you might recall (from a geometry class) the ratios of the lengths of sides of special right triangles.

Do the same thing for the second and third paths.

How far did she go in the x direction total? How far did she go in the y direction total?

Start a new coordinate system. Since your instructions are to do this graphically, this will be your answer (actually the previous exercises are not essential but will help you do this more accurately and make sure your answer is correct). Place the three paths (vectors) on the system, with the first starting at the origin, the second starting at the end of the first, and the third starting and the end of the second.

You should be able to construct a new right triangle with the resultant displacement being the hypotenuse and the x-axis and a vertical being the legs. Use this new triangle to answer the questions.