Simple relative motion

  • Thread starter jwxie
  • Start date
  • #1
jwxie
281
0

Homework Statement



Two ships, one moving 15 degree west of north with a speed 25 mi/h., the second moving 25 degree south of west with a speed 20 mi/h. relative to water pass each other. Find the velocity of the second ship relative to the first ship (magnitude and direction).

Homework Equations



V1 + r = V2
V2 - V1 = r

The Attempt at a Solution



I want to confirm on this.

My approach is using this relation.
V1 + r = V2
and so V2 - V1 = r, where r is the velocity we are looking for of our problem.

Then I will take components, x and y, and find sqrt(x^2+y^2) and direction tan-1 y/x
 

Answers and Replies

  • #2
tiny-tim
Science Advisor
Homework Helper
25,838
255
Hi jwxie! :smile:

(have a square-root: √ and try using the X2 and X2 tags just above the Reply box :wink:)
My approach is using this relation.
V1 + r = V2
and so V2 - V1 = r, where r is the velocity we are looking for of our problem.

Then I will take components, x and y, and find sqrt(x^2+y^2) and direction tan-1 y/x

Yes, that's exactly right! :smile:

(btw, I wouldn't use r, I'd stick to the same area of the alphabet, and use v12 or u or w :wink:)
 
  • #3
jwxie
281
0
Hi, tiny, thank you for your confirmation. My friend had an exam and he doubted about my explanation. Thank you!

I will make sure I check all the synatx ^^
 

Suggested for: Simple relative motion

Replies
8
Views
219
Replies
7
Views
149
Replies
9
Views
185
  • Last Post
Replies
2
Views
267
Replies
6
Views
510
  • Last Post
Replies
8
Views
577
  • Last Post
Replies
2
Views
66
Replies
7
Views
266
  • Last Post
Replies
5
Views
347
  • Last Post
Replies
7
Views
588
Top