physics
posted by Rony .
What is the force between two charged spheres 1.25 cm apart if the charge on one sphere is 2.50 C and the charge on other sphere is 1.75 X 10^8 C

Is there some failure of Coulomb's law here?
F=kQQ/r^2 
The two Q's in the Coulomb equation are different in this case.
Call them
Q1 = 2.50 C and
Q2 = 1.75 * 10^8 C .
I think you may have left out an exponent on Q1. 2.5 C is enough for a major lightning strike.
You may need to convert r to meters, depending upon which units
you use for k. 
how long did it take 4 u 2 knw physics

r is equal 1.25cm

A charge of 4.10 is placed at each corner of a square 0.100 on a side.
Determine the magnitude of the force on each charge.
Determine the direction of the force on each charge. Assume that the positive xaxis is directed to the right.