# Vector clock and vector dog displacement problems

1. Sep 14, 2009

### M1ZeN

1. The problem statement, all variables and given/known data
The minute hand on a watch is 2.00 cm in length. What is the length (in cm) of the i hat component of the displacement vector of the tip of the minute hand from 8:00 AM to 8:20 AM? What is the length (in cm) of the j hat component of the displacement vector of the tip of the minute hand from 8:00 AM to 8:20 AM?

2. Relevant equations

A^2 + B^2 = C^2

3. The attempt at a solution

I'm having trouble trying to find a geometric way of viewing the problem.
/\
l This is how I'm viewing 8:00 to 8:20 AM with only the minute hand.
l 2 cm
l
\
\ 2 cm
\
>

What I'm trying to figure out in the problem is what are the x and y components. My attempt is this:

x component
/\----
l l
l l
l l y component
\ l
\ l
\ l
>

I know from the tip of the minute hand at 8:00 AM to 8:20 AM is 2.8 cm, (2^2 + 2^2 = C^2, C = 2.8 cm)

1. The problem statement, all variables and given/known data
Jill's dog Sparky runs 70.0 m northeast to a tree, then 30.0 m west to a second tree, and finally 90.0 south to a third tree. Draw a picture and establish a coordinate system. Calculate the x component (in m) of Sparky's net displacement.
Calculate the y component (in m) of Sparky's net displacement.
Calculate the magnitude (in m) of Sparky's net displacement

2. Relevant equations

A^2 + B^2 = C^2

3. The attempt at a solution

For this problem, I'm again having trouble setting up values to put into an equation and viewing what in a picture is the x and y components. Here is a picture of how I'm attempting to view the problem with a coordinate system.

/\
l 30 m
-- l--------/
l l /
l 76.2 m l /
l l / 70.0 m
90 m l l /
l l /
<-------------------- l -------------------->
l l
l l
l l
l l
-- l
l
l
l
\/

Much thanks,
Daniel

2. Sep 14, 2009

### M1ZeN

Actually I'm clueless on putting the drawings I had for the problems into html so disregard the attempted pictures.

Last edited: Sep 14, 2009
3. Sep 14, 2009

### Redbelly98

Staff Emeritus
I can't make out your figure. But, how about using the angle made by the minute hand, and some trig, in order to get the x and y components of the hand's tip at the times listed (8:00 and 8:20)?