1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Homework Help: Scalar product of vectors

  1. Apr 1, 2012 #1
    1. The problem statement, all variables and given/known data

    Let vectorB= 5.45 m at 60°. Let C have the same magnitude as A and a direction angle greater than that of A by 25°. Let B·A = 32.4 m2 and B·C = 35.1 m2. Find the magnitude and direction of A .

    2. Relevant equations


    3. The attempt at a solution
    I just have one problem here. What do I use as theta? do i do cos 60?
    magnitude of b is 5.45 and that of a is unknown but what about the angle?
  2. jcsd
  3. Apr 1, 2012 #2


    User Avatar
    Science Advisor
    Homework Helper

    hi madinsane! :smile:
    θ is the angle between the two vectors

    you'll have to give the angle of A a name, ψ say, and then the angle of C is ψ + 25° :wink:
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook