It's time for santa to deliver his presents. assuming he delivers presents all over the world, he has to travel about 75,000,000 miles. if he travels east to west, he can use the time zones to make christmas day last 31 hours. what speed, in miles per hour, must santa fly to get all of his presents delivered?

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.