Magnitude of the force on this segment of wire ?

[mba444]

Homework Statement

A segment of wire carries a current of 15 A
along the x-axis from x = −6 m to x = 0 and
then along the z axis from z = 0 to z = 4.7 m.
In this region of space, the magnetic field is
equal to 78 mT in the positive z direction.
What is the magnitude of the force on this
segment of wire? Answer in units of N.

Homework Equations

F= i*l*B

The Attempt at a Solution

what i did is that i found F on the x-axis and i found F on the z-axis .. then i squared both of them and took the root as the final answer which is wrong

where is my mistake

 

[diazona]

It's hard to identify your mistake if you don't show your work