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### Matrices, Vectors, Velocity etc.

Posted:

**Fri Dec 11, 2009 11:14 pm**
by **k9ruby**

Anyone got a decent "Idiots guide" link to how to do these? Tried to get numerous lecturers to explain this to me, but they go through it way too fast. Any maths people want to help me?

### Re: Matrices, Vectors, Velocity etc.

Posted:

**Fri Dec 11, 2009 11:39 pm**
by **Remus**

I wish I could help Ruby but I haven't got a clue on Maths, I don't even know what that first word means!

Hopefully someone will be able to help you thought.

### Re: Matrices, Vectors, Velocity etc.

Posted:

**Sat Dec 12, 2009 12:09 am**
by **Brian**

Velocity is speed divided by distance, i think

### Re: Matrices, Vectors, Velocity etc.

Posted:

**Sat Dec 12, 2009 12:34 am**
by **Dan**

Brian wrote:Velocity is speed divided by distance, i think

Velocity IS speed I thought. I think speed/velocity is distance divided by time.

### Re: Matrices, Vectors, Velocity etc.

Posted:

**Sat Dec 12, 2009 1:09 am**
by **k9ruby**

Right. OK. I am going to ask you maths people for a rule, how I would go about the following using an EASY TO REMEMBER FORMULA WITH NO FUNNY LOOKING NUMBERS :

1) How to find somethings velocity after x time

2)

What is the X's initial velocity vector?

What is the X’s velocity vector when x = y?

What is the X's position vector when x = y?

3)

How to find out momentum when given mass and velocity

4)

What is the value of X, the speed of Y to the right after impact?

5)

How to find out an coefficient between X and Y

How to find the common speed

6) A really really simple explanation of what homowhatsit matrices are and transformations!

THANK YOU!!!!!!!!!!!!!!

### Re: Matrices, Vectors, Velocity etc.

Posted:

**Sun Dec 13, 2009 8:17 am**
by **Danni**

All the below coming from my fiancé, as I never did mechanics in AS Maths (as high as I went)

Velocity is speed in a given direction. It's a type of vector. Velocity = Change in displacement / time.

After that, the rest of the questions can't be answered without numbers of some kind. We know there are derivatives in there somewhere. Sorry we can't help more.

### Re: Matrices, Vectors, Velocity etc.

Posted:

**Wed Dec 16, 2009 12:13 am**
by **k9ruby**

Had test today and I think I got the jist of it. Will let you know on friday!

### Re: Matrices, Vectors, Velocity etc.

Posted:

**Thu Dec 17, 2009 12:51 pm**
by **Thirteen-thirty-seven**

*hugs* I'm glad you got it.

### Re: Matrices, Vectors, Velocity etc.

Posted:

**Thu Dec 17, 2009 3:07 pm**
by **Alice**

Dan wrote:Brian wrote:Velocity is speed divided by distance, i think

Velocity IS speed I thought. I think speed/velocity is distance divided by time.

Youe both kind of wrong I'm afraid.

Velocity is distance over time, but it is not the same as speed. Velocity is speed in a given direction. So you can have a change in velocity without a change in speed. That's why an object moving in a circle can be said to be accelerating.