Two tiny spheres of mass = 8.70 mg carry charges of equal magnitude, 72.0 nC , but opposite sign. They are tied to the same ceiling hook by light strings of length 0.530 m . When a horizontal uniform electric field E that is directed to the left is turned on, the spheres hang at rest with the angle between the strings equal to 50 in the following figure. (note that q1 is positive and it is the left once)

http://session.masteringphysics.com/problemAsset/1331112/7/21-82.jpg

What is the magnitude E of the field?

Question

Two tiny spheres of mass  = 8.70 mg  carry charges of equal magnitude, 72.0 nC , but opposite sign. They are tied to the same ceiling hook by light strings of length 0.530 m . When a horizontal uniform electric field E that is directed to the left is turned on, the spheres hang at rest with the angle  between the strings equal to 50 in the following figure. (note that q1 is positive and it is the left once)
	
http://session.masteringphysics.com/problemAsset/1331112/7/21-82.jpg

What is the magnitude E of the field?

anonymous · Answer

$$E=5,52\times10^{5}\frac{ N }{ C }$$

This result may be wrong because of complicated math. It needs to be checked.

anonymous · Answer

result is 555415 si unit.here we not only have to calculate the attraction of the spheresdue to electric field but also the attraction due to there own charge.so calculating this this will be the answer|dw:1387528205333:dw|