How is this wrong? Physics help please!
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How is this wrong? Physics help please!

[From: ] [author: ] [Date: 12-10-31] [Hit: ]
4 N and the Y axis to be 367.I did -40.4^2 + 376.8^2 then square rooted that answer to get 365.574 N but the answer is wrong, please explain how you found the displacement if you got a different answer!......
A crate is pulled to the right with a force of
72.1 N, to the left with a force of 112.5 N,
upward with a force of 599 N, and downward
with a force of 231.2 N.

What is the magnitude of the net external
force on the crate?

I found the X axis to be -40.4 N and the Y axis to be 367.8N
I did -40.4^2 + 376.8^2 then square rooted that answer to get 365.574 N but the answer is wrong, please explain how you found the displacement if you got a different answer!

-
Force in x-direction is 72.1 - 112.5 = -40.4N
Force in y-direction is 599 - 231.2 = 367.8N

Resultant = √(-40.4)² + (367.8)²)
= √(1632.16 + 135276.84)
= √136909
= 370N

The mistake you have made is working out (-40.4)².
You have used -1632.16 but there should be no minus sign. When you square a negative number the answer is positive.

-
I used the component method to answer this question.
In order to use the component method, we need to set a positive and negative direction.

Up and Right are positive. Just so you know, which are positive or negative is arbitrary.
Down and Left are negative.

F net (positive) = 72.1 N + 599 N
F net (positive) = 671.1 N

F net (negative) = -112.5 N + -231.2 N
F net (negative) = -343.7 N

F net = sqrt((671.1 N)^2 + (-343.7 N)^2))
F net = 349.67 N

I'm not exactly sure how to find the displacement.
1
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