Along wire carries a current density proportional to the distance from its center, j=(jo/ro)•r, where jo and ro are constants appropriate units. determine the magnetic field vector inside this wire.

Engineers find a new metal that is stronger than steel but much lighter. this material is also significantly cheaper than what is currently used for most aircraft, available in large quantities, and easy to manufacture. the engineers are excited because this new material will lower the costs of buying and operating airplanes for companies. what is probably the best step for the engineers to make next?