You are Here: Home >< Maths

# statics of a particle M1 watch

1. Forces P, Q and R act on a particle at the origon O. find the magnituide of the resultant and the angle it makes with Ox.

a) P= 2i + 5j
Q= 3i + 4j
R = 5i + 2j

i know to find the manitutde of the reusltant, you use phytag, and to find the angle its normally Tan x = opp/adj

but how do you do this with the i and j??

Thanks.
2. Well what are i and j? They are the unit vectors in the x and y direction. So you know that you have a vector that has magnitude 10 in the x-direction, and magnitude 11 in the y-direction. What triangle do these two components give, and what is the angle made with the Ox?
3. (Original post by Kolya)
Well what are i and j? They are the unit vectors in the x and y direction. So you know that you have a vector that has magnitude 10 in the x-direction, and magnitude 11 in the y-direction. What triangle do these two components give, and what is the angle made with the Ox?
oh right, i only thought to use phytag for the reusltant only! so we use it the same way for all 2 sides of the right angle triange and then use trig?
4. I don't know what "phytag" is.
5. (Original post by Kolya)
I don't know what "phytag" is.
pythag?
6. Just use tan(t)= o/a , as you said...
7. (Original post by Kolya)
Just use tan(t)= o/a , as you said...
ok, thanks a lot!

### Related university courses

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:
Updated: November 8, 2008
Today on TSR

### He broke up with me because of long distance

Now I'm moving to his city

### University open days

Wed, 25 Jul '18
2. University of Buckingham
Wed, 25 Jul '18
3. Bournemouth University
Wed, 1 Aug '18
Poll
Useful resources

### Maths Forum posting guidelines

Not sure where to post? Read the updated guidelines here

### How to use LaTex

Writing equations the easy way

### Study habits of A* students

Top tips from students who have already aced their exams