.An 850 turn solenoid with a diameter of 7.0cm is 21 cm long with 42A of current. A long straight wire cuts through the center of the solenoid, along a diameter. This wire carries a 22A current upward. What is the force on this wire assuming the solenoid's field points due east

The answer is that there is no magnetic force on the wire. The force on a wire is the cross product of the current thru it and the magnetic field it is in. In your case, both are parallel and the cross product is therefore zero.

Explanation:

F = (n x i)2 x magnetic constant x a / (2 x g2)

Where,

F = Force, i = Current, g = Length of the gap between the solenoid and a piece of metal, a = Area n = Number of turns, Magnetic constant = 4 x PI x 10-7.

no. dot product   =0 when vecs at right angles