Hey there! Sign in to join this conversationNew here? Join for free
x Turn on thread page Beta
    • Thread Starter
    Offline

    11
    ReputationRep:
    Name:  M2.png
Views: 141
Size:  120.9 KB
    Hi, when working out Newtons law of restitution you use the relative speeds of separation and approach. However, for this question, on the last line of working in the image, how come the speed of separation is v2 - v1 and not v2 + v1 as they are moving away from each other?Do you always take the two speeds away when you have unknown values for the velocities?
    Thanks for the help!
    Offline

    11
    ReputationRep:
    It shouldn't matter. If you use - , then v1 will have a positive value and vice versa, I think!
    (Well, I'm screwed for M2 this year!)
    Offline

    14
    ReputationRep:
    (Original post by Glavien)
    Name:  M2.png
Views: 141
Size:  120.9 KB
    Hi, when working out Newtons law of restitution you use the relative speeds of separation and approach. However, for this question, on the last line of working in the image, how come the speed of separation is v2 - v1 and not v2 + v1 as they are moving away from each other?Do you always take the two speeds away when you have unknown values for the velocities?
    Thanks for the help!
    Judging by the arrows, they've chosen to take both v1 and v2 to the right, since you don't know when you start which way they'll be going after the impact (mind you, it doesn't help that they've put their arrow for the 8 going the wrong way).
    • Thread Starter
    Offline

    11
    ReputationRep:
    (Original post by tiny hobbit)
    Judging by the arrows, they've chosen to take both v1 and v2 to the right, since you don't know when you start which way they'll be going after the impact (mind you, it doesn't help that they've put their arrow for the 8 going the wrong way).
    Thanks man!


    Posted from TSR Mobile
 
 
 
Reply
Submit reply
Turn on thread page Beta
Updated: April 2, 2016
Poll
Do you agree with the proposed ban on plastic straws and cotton buds?
Useful resources

Make your revision easier

Maths

Maths Forum posting guidelines

Not sure where to post? Read the updated guidelines here

Equations

How to use LaTex

Writing equations the easy way

Student revising

Study habits of A* students

Top tips from students who have already aced their exams

Study Planner

Create your own Study Planner

Never miss a deadline again

Polling station sign

Thinking about a maths degree?

Chat with other maths applicants

Can you help? Study help unanswered threads

Groups associated with this forum:

View associated groups

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

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