A square frame carrying a current \(I=0.90 \mathrm{~A}\) is located in the same plane as a long straight wire carrying a current \(I_{0}=\) \(=5.0\) A. The frame side has a length \(a=8.0 \mathrm{~cm} .\) The axis of the frame passing through the midpoints of opposite sides is parallel to the wire and is separated from it by the distance which is \(\eta=1.5\) times greater than the side of the frame. Find: (a) Ampere force acting on the frame; (b) the mechanical work to be performed in order to turn the frame through \(180^{\circ}\) about its axis, with the currents maintained constant