Thread: vectors

an object P is acted upon by 3 coplanar forces one force is a hundred pounds due south another is 150 pointing due east and the third is 200 lbs 30 degrees north of east. What is the force needed to prevent P from moving

Hello, leinadwerdna!

Do you know how to write vectors and add vectors?

An object is acted upon by 3 coplanar forces.
One force is 100 pounds due south,
another is 150 pounds due east
and the third is 200 pounds 30° north of east.
What is the force needed to prevent from moving?

Code:

                          w
                        *
              200   *
                *
        P   * 30°
        o - - - - - - * v
        |     150
    100 |
        |
        *
        u

We have: .


The resultant vector is: .

is moving directly east with a force of pounds


To prevent movement, pounds of force must be applied directly west.
. . The applied vector would be: .

Shouldn't this:

Originally Posted by Soroban

The resultant vector is: .

Be this?

the answer in the book is 323 lbs due west not equivalent to either of the answers u two gave. what is wrong

I edited my previous post. Check the answer now, it should be correct.

ok i get that but how do u know the force must be applied due west to stop the object