A rock is dropped into a graduated cylinder containing 40 mL of water. The new volume is 47 mL. What is the volume of the rock?
4 mL
7 ml

87 ml

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.