Physics Kinematic Problem - need help

1. Jun 21, 2005

firstwave

Physics Kinematic Problem -- need help

Well here I am studying for the final and this question pops up and I have no idea how to do it. I know the answer however, but it does not realy help me.

If you walk 6.0 km in a straight line in a direction north of east and you end up 2.0 km east and several kilometers north. How many degrees north of east have you walked?

Choices:

a) 19 degrees
b) 45 degrees
c) 60 degrees
d) 71 degrees

2. Jun 21, 2005

Delta

The trig to this is to try drawing the walk on a piece of paper.

3. Jun 21, 2005

FredGarvin

Did you draw a diagram? I drew a triangle with a vertex at the origin and the hypotenuse going north and east (up and to the right) for 6 units. The opposite side would be 2 units....Can you finish from there?

4. Jun 21, 2005

firstwave

would it be possible to draw it in the forum?? I still don't get it. I knew how to do this a while ago and it was pretty easy. I did draw a diagram but it didn't really help for some reason. Maybe I read the question wrong, but either way I still don't understand.

AH HA!! Thanks Fred. When you said 'opposite' I thought it meant opposite side of the plane. Ah it means the opposite side. Ok thanks I get it.

Cos -1 (2/6) = 71

:D

Thanks again

Last edited: Jun 21, 2005
5. Jun 22, 2005

Dr.Brain

This is simple. First you walk 6km north of east, you end up 2km east and some km's north . Draw a triangle representing the above values where base=2 and hypotenuse=6

therefore,

$cosQ= \frac{1}{3}$