\"Two small 0.1g styofoam balls are strung like beads on a vertical insulating t

Question

"Two small 0.1g styofoam balls are strung like beads on a vertical insulating thread. The lower ball is glued to the thread but the upper ball is free to move. Imagine that both are given an equal amount of negative charge such that the upper ball is suspended above the lower with their centers 4.0cm apart. (assume that each ball repels the other as if it were a point charge located at its center) Roughly how many electrons have been added to each ball?"

If you can please show your work in steps it would help me greatly and if you can give your reasoning along with it. Thank you for your time.

Explanation / Answer

Here,

m = 0.1 gm = 1 *10^-4 Kg

d = 4 cm = 0.04 m

let the number of electrons added is n

for balancing the forece on upper ball

m * g = k * (n * e)^2/(d^2)

1 *10^-4 * 9.8 = 9*10^9 * (n * 1.602 *10^-19)^2/(0.04)^2

solving for n

n = 8.24 *10^10

the number of electrons added is 8.24 *10^10

Related Questions

Navigate

• Browse (All)
• Browse #
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.