Calculating Induced Voltage in a Flying Airplane through Earth's Magnetic Field

[BadatPhysicsguy]

Homework Statement

Assuming you know general specifications of the airplane such as span of the wings and maximum speed, calculate the voltage that is induced when the airplane is flying horizontally through Earth's magnetic field where both the horizontal component and vertical component of Earth's magnetic field is known.

Homework Equations

This is to be written in general form. Since I know the span of the wings, the speed and the magnetic field's strength the formula is

e = lvB

The Attempt at a Solution

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I have the formula e = lvB ready. The only thing I have to decide is whether to use the horizontal or the vertical component of Earth's magnetic field. Since the plane is flying horizontally, the component in the horizontal direction wouldn't affect the plane. Therefore, it is the vertical component.

So the solution would be e = lvB with the vertical component. However, I doubt this is correct. Can it really be so easy?

 

[mfb]

Since the plane is flying horizontally, the component in the horizontal direction wouldn't affect the plane.

There are two horizontal directions.
Your answer is still correct, but the argument needs one more detail.