What must be the charge on each of a pair of pith balls suspended in air from the same point - Physics - Electric Charges And Fields

Question

What must be the charge on each of a pair of pith balls
suspended in air from the same point by strings 10 cm long if they
repel each other to a separation of 8 cm? Mass of each pith ball is
1 gram and accleration due to gravity is 9 8
m/s2

Jyoti Pant · Accepted Answer

Given,
Mass of each ball=1 g=0
001 kgAcceleration due to gravity, g=9
8 m/s2Length of strings=10 cm=0
10 mSeparation between strings=8 cm=0
08 mForce of repulsion is balanced by the sin component of the tension in the string
F=T sin θ---(i)Weight is balanced by the cos component of the tension
mg=Tcosθ---(ii)F=mg tanθsin θ=0 08/20 10=0
040
10=410=25cosθ=52-225=25-45=215secθ=521tan θ=25×521=221So, F=mgtanθ=0
001×9 8×221=0 01964 58=0
0043 NAlso, F=kq2r2or q2=Fr2k=0 0043×0
0829×109=4
3×10-3×8×8×10-49×109=30
57×10-16q=5 53×10-8C

What must be the charge on each of a pair of pith balls suspended in air from the same point by strings 10 cm long if they repel each other to a separation of 8 cm? Mass of each pith ball is 1 gram and accleration due to gravity is 9.8 m/s2

What must be the charge on each of a pair of pith balls suspended in air from the same point by strings 10 cm long if they repel each other to a separation of 8 cm? Mass of each pith ball is 1 gram and accleration due to gravity is 9.8 m/s²