How to Calculate Magnetic Flux Through a Desk?

[mrlucky0]

Homework Statement

A horizontal desk surface measures 4.3 m by 2.0 m. If the Earth's magnetic field has magnitude 0.32 mT and is directed 45° below the horizontal, what is the magnetic flux through the desk surface?

Homework Equations

Flux = B*A*Cos(a)

Where A is the area, B is the magnetic field,

The Attempt at a Solution

Flux = B*A*Cos(a)
= (.32E-3 T) * (4.3*2.0 m^2) * ( Cos(45) )
= 0.00194596 T*m

However, the my solution isn't correct and I'm convinced that I'm not doing anything incorrectly.

 

[dynamicsolo]

The Attempt at a Solution

Flux = B*A*Cos(a)
= (.32E-3 T) * (4.3*2.0 m^2) * ( Cos(45) )
= 0.00194596 T*m

I don't see anything wrong with your calculation either (other than that the units of flux should be T·(m^2).

I am a bit troubled by the value given for the magnetic field strength. For Earth, this value should be more like 30-60 microteslas or 0.03-0.06 mT. Are you sure about the location of the decimal point in the problem?