Aurora national Science High School
posted by Jezrell on .
a +4C charge is 400m along the horizontal line toward the right of a 3C charge. Calculate the E at a point 300m above the negative charge. ASAP please. It's 7:48pm here and I need it tomorrow at 7am. Thanks.

It is a simple problem, the E vectors add as vectors.
First the E from the negative charge.
E1=kq/r^2=3Ck/300^2 in the direction of downward.
E2= k(4c)/500^2 in the direction of theta
where Theta=arc tan 300/400 to the left of the upward direction.
E2=4k/500^2 (upward sintheta+left costheta)
E2=4k/500^2 ( 300/500 upward+400/500 to left) check my mental calculations
now add E1+E2 
Thanks