Hey there! Sign in to join this conversationNew here? Join for free to post

Vector Products

Announcements Posted on
Last day to win £100 of Amazon vouchers - don't miss out! Take our quick survey to enter 24-10-2016
    • Thread Starter

    Hi Everyone,

    Quick question regarding vector cross products.

    Im looking at the question:

    The vector a points east with magnitude 2, and the b points north-west with magnitude 3. Wha is the magnitude and direction of c = a x b?

    Now the mangitude was easy to calculate, 3*(2^1/2). However im having trouble with the direction.

    We've been taught the right hand rule, but does that only work if vectors a and b are perpendicular and your in a 3D coordinate system?

    The answer is 'points up'... very specific, so im guess that means north?

    Or would you in a case like this when a and b are not perpendicular would you use geometry to calculate which direction the cross product would be in?

    Cheers for any help guys
Write a reply…


Submit reply


Thanks for posting! You just need to create an account in order to submit the post
  1. this can't be left blank
    that username has been taken, please choose another Forgotten your password?
  2. this can't be left blank
    this email is already registered. Forgotten your password?
  3. this can't be left blank

    6 characters or longer with both numbers and letters is safer

  4. this can't be left empty
    your full birthday is required
  1. Oops, you need to agree to our Ts&Cs to register
  2. Slide to join now Processing…

Updated: May 16, 2016
TSR Support Team

We have a brilliant team of more than 60 Support Team members looking after discussions on The Student Room, helping to make it a fun, safe and useful place to hang out.

Would you rather find
Study resources

The Student Room, Get Revising and Marked by Teachers are trading names of The Student Room Group Ltd.

Register Number: 04666380 (England and Wales), VAT No. 806 8067 22 Registered Office: International House, Queens Road, Brighton, BN1 3XE

Reputation gems: You get these gems as you gain rep from other members for making good contributions and giving helpful advice.