Acharged particle moves through a velocity selector at a constant speed in a straight line. the electric field of the velocity selector is 3.50 × 10 3 n/c, while the magnetic field is 0.270 t. when the electric field is turned off, the charged particle travels on a circular path whose radius is 4.70 cm. find the charge-to-mass ratio of the particle.

Point charges q1=+2.00μc and q2=−2.00μc are placed at adjacent corners of a square for which the length of each side is 1.50 cm . point a is at the center of the square, and point b is at the empty corner closest to q2. take the electric potential to be zero at a distance far from both charges. part a what is the electric potential at point a due to q1 and q2? express your answer with the appropriate units.