Understanding vectors, direction, and magnitude

[ducks10]

Hi, I need some help

Homework Statement

Three kids are pulling on a poor teddy bear. Andy is pulling with a force of 10N in the North direction. Ben is pulling with %N straight South, and Charlie is pulling with 8N in the West direction
a) which direction will they move
b) In what direction with what force should david pull to make sure the teddy bear doesn't move?

Homework Equations

A=Ax+Ay

The Attempt at a Solution

Rx= 8N+0N, Ry= 10N + 5N
North west direction?

Please :)

 

[lewando]

Step 1: Draw a picture of what is going on, before David arrives on the scene.
Step 2: Using this picture, what are the sum of forces applied to the bear in the x direction? The y direction?

Additional steps to be supplied when you get step 2 correct.

 

[Redbelly98]

Welcome to Physics Forums.

Hi, I need some help

Homework Statement

Three kids are pulling on a poor teddy bear. Andy is pulling with a force of 10N in the North direction. Ben is pulling with %N straight South, and Charlie is pulling with 8N in the West direction
a) which direction will they move
b) In what direction with what force should david pull to make sure the teddy bear doesn't move?

Homework Equations

A=Ax+Ay

The Attempt at a Solution

Rx= 8N+0N, Ry= 10N + 5N
North west direction?

Please :)

I don't think "north west" is specific enough, they probably want to know how many degrees from north it will move.

When you calculate Rx and Ry, you need to keep track of whether each force is treated as positive or negative. Usually north or east are positive, while south or west would be negative.