Find the x-component of the magnetic force on the wire

[Charanjit]

1. Homework Statement :
A wire with a length of 29.0 cm lies along the z-axis and carries a current of 9.00 A in the +z-direction. The magnetic field is uniform and has components Bx = -0.204T, By = -0.968T, and Bz = -0.328 T

Homework Equations

1. Find the x-component of the magnetic force on the wire. Ans: 2.5N
2. Find the y-component of the magnetic force on the wire Ans: -0.532N
3. Find the z-component of the magnetic force on the wire
4. What is the magnitude of the net magnetic force on the wire?



3. The Attempt at a Solution .
I solved question 1 and 2. But I don't fully understand why. For question 1 I used the force in the y direction and in 2 I used the force in the x direction. But why like that?
For #3, I used the z direction force, and its not correct. So kind of confused.

 

[Juan Pablo]

The force on a wire in magnetic field B is given by

$$\vec{F_B} = I \vect L \times \vect B$$ where L is a vector that points in the direction of the current and magnitude the length of the wire.

So,

$$\vec{L} = 0.29k$$
$$\vec B = -2.04i-0.968j-0.328k$$

Compute the cross product using a determinant.

 

[Charanjit]

Oh ok, kind of forgot myu calculus a bit. Read over my notes from Cal class, makes sense now. Thanks.