Five equal charges Q=8 C are equally spaced on a semicircle of radius R=5 cm as shown in the Figure. Calculate the force on a charge q=7 C located at the center of the semicircle. (Your result must be in multiples of 1013 Newtons. That means if you get a result of 9.2 x 10 just type 9.2 in the answer box. Include 1 digit after the decimal point and maximum of 5% of error is accepted in your answer. Take k=9x10.)