You are playing catch with a friend in a moving train. when you toss the ball in the direction the train is moving, how does the speed of the ball appear to an observer standing at rest outside the train?

i know it appears to be traveling faster than the train, but i don't know the technicalities

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.