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

where are you getting confused?

anonymous · Answer

what does the left part of the bottom equation say? 
"(K*(q*q))/_*(sin(theta))squared"?
what is the symbol by sin square theta? Thank you