Four point charges are at the corners of a square of side a as shown in the figure. (a) Determine the magnitude
and direction of the electric field at the location of
charge q. (b) What is the resultant force on q?

Aparticle initially located at the origin has an acceleration of = 2.00ĵ m/s2 and an initial velocity of i = 8.00î m/s. find (a) the vector position of the particle at any time t (where t is measured in seconds), (b) the velocity of the particle at any time t, (c) the position of the particle at t = 7.00 s, and (d) the speed of the particle at t = 7.00