You are Here: Home >< Physics

Change in velocity?

1. 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

2. (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
3. (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

Register

Thanks for posting! You just need to create an account in order to submit the post
1. this can't be left blank
2. this can't be left blank
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
1. Oops, you need to agree to our Ts&Cs to register

Updated: June 2, 2012
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.

This forum is supported by:
Today on TSR

Help!

Will Oxford nullify my offer?