An infinite wire and an infinite length conductor sheet are carrying currents I1 and I2, respectively. Both are placed parallel to the the z axis with the wire coinciding with the z axis. The conductor sheet has a semi-circle cross-section with radius b and negligible thickness. Derive an expression for the unit-length force acting on the conductor sheet due to the current passing in the wire.

Adiver named jacques observes a bubble of air rising from the bottom of a lake (where the absolute pressure is 3.50 atm) to the surface (where the pressure is 1.00 atm). the temperature at the bottom is 4.00 ∘c, and the temperature at the surface is 23.0 ∘c. what is the ratio of the volume of the bubble as it reaches the surface (vs) to its volume at the bottom (vb)? if jaques were to hold his breath the air in his lungs would be kept at a constant temperature. would it be safe for jacques to hold his breath while ascending from the bottom of the lake to the surface?