1. What is the resistance of a 2.9-mm length of copper wire 1.6 mm in diameter?

The resistivity of copper is 1.6810?8 ? ? m

Express your answer to two significant figures and include the appropriate units.

2.

Part A At a point high in the Earth's atmosphere, He'll ions in a concentration of 2.5 x 1012/m are moving due north at a speed of 2.0 x 10 m/S. Also, a 7.2 x 10" /m concentration of Of ions is moving due south at a speed of 6.4 x 10 m/s. Determine the magnitude of the net current passing through unit area (A/m). Express your answer using two significant figures. Templates Symbols Undo redo reset keyboard shortcuts Help A/m Submit Previous Answers Request Answer X Incorrect; Try Again Part B Determine the direction of the net current. O West O East O South North Submit Request