Join TSR now and get all your revision questions answeredSign up now

Change in velocity? Watch

    • Thread Starter
    Offline

    0
    ReputationRep:
    When drawing a vector diagram, I have been told to use the tip-to-tail rule

    However, as per this attachment, the change in velocity (which is a vector) does not seem to use this rule. indeed change in v (the horizontal line) has magnitude VB - Va.

    Why is this?
    Attached Images
     
    Offline

    2
    ReputationRep:
    (Original post by ilovemath)
    When drawing a vector diagram, I have been told to use the tip-to-tail rule

    However, as per this attachment, the change in velocity (which is a vector) does not seem to use this rule. indeed change in v (the horizontal line) has magnitude VB - Va.

    Why is this?
    It is using the tip-tail rule, it's just you're adding the wrong way round.

    Tip to tail is for a+b=c with the tails of a and c starting at the origin, and the tip of a and the tail of b coinciding, and the tips of b and c coinciding.

    for change in velocity the equation is va+dv=vb and as you can see from your diagram the tip of va and tail of dv do coincide
    • Thread Starter
    Offline

    0
    ReputationRep:
    (Original post by The Mr Z)
    It is using the tip-tail rule, it's just you're adding the wrong way round.

    Tip to tail is for a+b=c with the tails of a and c starting at the origin, and the tip of a and the tail of b coinciding, and the tips of b and c coinciding.

    for change in velocity the equation is va+dv=vb and as you can see from your diagram the tip of va and tail of dv do coincide
    oh I see
 
 
 
Poll
What is your favourite film genre?

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

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