In VPython,

A proton moves with a constant velocity of 4 10⁴ m/s in the +x direction, along the x axis, starting at an initial location of 4 10¹⁰,0,0 m.

(a) Write a program that calculates and displays the magnetic field of the moving proton at four observation locations in the yz plane (two on the y axis and two on the z axis), each a distance of 8 10¹¹ m from the x axis. Use cyan arrows to represent the magnetic field.

(b) Does the magnetic field at one of your fixed observation locations change or stay constant?

(c) What do you observe if you change the speed of the proton?

(d) What do you observe if you change the proton to an antiproton?