two charged pith balls are suspended on very light 10cm strings. Each has a mass of 30g. In equilibrium, the total angle between the strings is 60 degrees. Assuming the pith balls are equally charged, what is the charge on each ball?
2007-10-02 14:49:05 · 1 answers · asked by Anonymous in Science & Mathematics ➔ Physics
ok, so I know I have to use Coulomb's law.
F = [(8.9875 x 10^9) q1]/ (radius^2)
but I don't know how to find the force.
(q1 is the charge)
Help is will be much appreciated!!
2007-10-02 15:28:38 · update #1
You are on the right track
however
F = [(8.9875 x 10^9) (q1)^2]/ (radius^2)
also F is equal to the horizontal component of weight
F=mg sin(30)
finally
q= sqrt( mg sin(30) R^2 / k)
Do you wonder what is R? well
R= 2x10cm sin(30)
The rest is cake...
2007-10-03 13:33:14 · answer #1 · answered by Edward 7 · 0⤊ 0⤋