Question

What equation do I use to find this? Thanks

The x and y components of a certain force are measured and found to be Fx = 68 ± 3N and Fy = 42 ± 2 N, respectively. Calculate the error associated with the magnitude of this force?

Answer 1

Well Magnitude is

sqrt((Fx^2 + Fy^2))

where:
Fx is the sum of all forces in x-direction
Fy is sum of all forces in y-direction

Solution:
Fx = 68 + 3 = 71N
Fy= 42 + 2 = 44 N

Magnitutde:
sqrt((71^2+44^2)) = 83.53

Fx=68 - 3 = 65N
Fy = 42 - 2 = 40 N

Magnitude:
sqrt((65^2+40^2)) = 76.32 N


For error:

(Max Force - Min Force)/(Max Force) * 100 = % error

(83.53 - 76.32)/(83.53) * 100 = 8.63%

Which means The magnitude of the addition part is 8.63% bigger than the subtraction part.