(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

Two identical small spheres of mass 2.0g are fastened to the ends of an insulating thread of length 0.60m. The spheres are suspended by a hook in the ceiling from the centre of the thread. The spheres are given identical electric and hang in static equillibrium, with an angle of 30 degrees between the string halves. Calculate the magnitude of the charge on each sphere.

Basically looks like a triangle with the top corner angle 30 degrees, and both sides 0.3m each with the bottom side unknown which is r.

-Consider the 3 forces acting on the sphere

-Resolve the tension in the x and y directions

-Find FE

-Find r

-Apply Coulomb's Law

Given: m = 0.002 kg

r = ?

theta = 30 degrees

s1 = 0.3m

s2 = 0.3m

q = ?

FE = ?

2. Relevant equations

Sin (theta) = Opp/Hyp

Cos(theta)= Adj/Hyp

Sum of all forces in the x and y directions = ma

FE = kq1q2/r^2

3. The attempt at a solution

Sin theta = Opp/Hyp

0 = sin(theta) X Hyp

= sin 15 X .3m

=0.0776 X 2

= 1.55m

Fe = Kq1q2/r^2

Thats how far I got, I know im supposed to find the force of tension some how but not sure

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# Homework Help: Calculate the magnitude of the charge on each sphere

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