Magnetic force, parallel wires, and the ampere?

Question

In the diagram, one current flows through the straight wire and another current flows around the wire loop, with the magnitudes shown. What are the magnitude and direction of the force exerted on the wire loop by the current in the straight wire?

See diagram

http://i338.photobucket.com/albums/n418/gregismighty/p9e.jpg

Answer 1

If you integrate and plug in the values, you get:

F = (µ₀I1I2L / 2π) x ((a / b) / (a + b))

= (((4π x 10^-7 Tm/A) x 3.50 A x 2.00 A x 1.00 m) / (2 x π)) x (0.500 m / 0.500 m) / (0.500 m + 0.500 m))

= (1.40 x 10^-6 N/m) x 1.00 m

= 1.40 µN

The direction is towards the long, straight wire.