• Support PF! Buy your school textbooks, materials and every day products Here!

I don't get scalar product?

  • Thread starter elpermic
  • Start date
  • #1
29
0

Homework Statement


Find the scalar product of the 2 vectors.
Vector A is north of east at 70 degrees with a magnitude of 3.60m
Vector B is south of west at 30 degrees with a magnitude of 2.40m


Homework Equations


ABcosx


The Attempt at a Solution


I did dot product using the formula, 3.60x2.40xcos(-100) and got the wrong answer.. The answer is 13.00. What the hell did I do wrong? I did as the formula said I should do and failed. I don't get it??
 
Last edited:

Answers and Replies

  • #2
tiny-tim
Science Advisor
Homework Helper
25,832
249
Vector A is north of east at 70 degrees …
Vector B is south of west at 30 degrees …

I did dot product using the formula, 3.60x2.40xcos(-100) …
Hi elpermic! :smile:

It ain't 100. :wink:
 
  • #3
Doc Al
Mentor
44,865
1,111
I did dot product using the formula, 3.60x2.40xcos(-100) and got the wrong answer.. The answer is 13.00.
(1) The formula calls for the angle between the two vectors. That angle is not 100°. (Draw a diagram.)
(2) The answer cannot be 13.
 

Related Threads for: I don't get scalar product?

  • Last Post
Replies
24
Views
4K
  • Last Post
Replies
11
Views
2K
  • Last Post
Replies
3
Views
2K
  • Last Post
Replies
12
Views
5K
  • Last Post
Replies
5
Views
3K
  • Last Post
Replies
13
Views
2K
  • Last Post
Replies
1
Views
2K
  • Last Post
Replies
18
Views
6K
Top