question.rb1 question :two_parallel_wires do2   kind :numerical3   describes "Two long and parallel straight wires A and B carrying currents of %{current_a} and %{current_b} in the same direction are separated by a distance of %{separation}. %{force}, in newtons?"4   given current_a: "8.0 A"5   given current_b: "5.0 A"6   given separation: "4.0 cm"7   asks force: "Estimate the force on a 10 cm section of wire A"8 end

solution.rb1 solve :two_parallel_wires, using: [MagneticForce, MagneticFieldOfCurrents] do2   objects :wire_a, :wire_b3 4   take current_a: wire_a.current5   take current_b: wire_b.current6   take separation: wire_a.distance_from_the_wire(from: wire_b)7 8   deduce_from "a 10 cm section", wire_a.length_in_the_field => "10 cm"9 10   B = wire_b.field_near_a_wire(at: wire_a)11   force_on_a_section = wire_a.force_on_a_wire(by: wire_b, length: wire_a.length_in_the_field)12 13   answer force_on_a_section:, in: "N", figures: 214 15   conclusion "Parallel wires carrying currents in the same direction attract each other; the magnetic field from one wire acts on the other."16 end