Scientists in a test lab are testing the hardness of a surface before constructing a building. calculations indicate that the entire structure would sink by a certain amount for every additional floor that is added. if the maximum permissible limit for depression of the structure is 20 centimeters, how many floors can be safely added to the building?

Along wire carrying a 4.2 a current perpendicular to the xy-plane intersects the x-axis at x=−1.7cm. a second, parallel wire carrying a 3.0 a current intersects the x-axis at x=+1.7cm. part a at what point on the x-axis is the magnetic field zero if the two currents are in the same direction? express your answer to two significant figures and include the appropriate units.