You are Here: Home >< Maths

# edexcel i-al june 2015 m1

Announcements Posted on
Last day to win £100 of Amazon vouchers - don't miss out! Take our quick survey to enter 24-10-2016
1. I'm stuck on the first part. I managed to combine the equation and get k=3u/3u + v. how can i prove k < 1 from there?
Attached Images
2. WME01_01_que_20150603 (dragged) 1.pdf (52.1 KB, 38 views)
3. (Original post by jamesw5555)
I'm stuck on the first part. I managed to combine the equation and get k=3u/3u + v. how can i prove k < 1 from there?
V must be greater than 0 traveling in the positive direction so your equation can never be greater than 1.
4. (Original post by jamesw5555)
I'm stuck on the first part. I managed to combine the equation and get k=3u/3u + v. how can i prove k < 1 from there?
Here is how I would do it:

[EDIT: Made a mistake, see corrected version below]
5. (Original post by Middriver)
You lost a K from the Z on the second step?
Aargh, you're right. Let's try again:

-Initial momentum of A = 2mu
-Initial momentum of B = -3kmu

-Final momentum of A = -mu
-Final momentum of B = zkmu

where z is a positive constant (it has to be positive as particle B is travelling in the opposite direction to A).

So, using conservation of momentum:

Initial momentum = final momentum
=> 2mu - 3kmu = zkmu - mu
=> 2 - 3k = kz - 1
=> 3 = k(z+3)
=>3/(z+3) = k

And since z > 0, then k < 1.
6. (Original post by Ollie231213)
Aargh, you're right. Let's try again:

-Initial momentum of A = 2mu
-Initial momentum of B = -3kmu

-Final momentum of A = -mu
-Final momentum of B = zkmu

where z is a positive constant (it has to be positive as particle B is travelling in the opposite direction to A).

So, using conservation of momentum:

Initial momentum = final momentum
=> 2mu - 3kmu = zkmu - mu
=> 2 - 3k = kz - 1
=> 3 = k(z+3)
=>3/(z+3) = k

And since z > 0, then k < 1.
Ah okay now i understand it, i got the same thing as your last step but it was 3u/3u+z but you cancelled the mu to make it easier to work with. Thx for the help!

## 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: May 31, 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.

This forum is supported by:
Today on TSR

### How does exam reform affect you?

From GCSE to A level, it's all changing

Poll
Useful resources

### Maths Forum posting guidelines

Not sure where to post? Read here first

### How to use LaTex

Writing equations the easy way

### Study habits of A* students

Top tips from students who have already aced their exams