# Physics

posted by
**John**
.

Three identical small Styrofoam balls of mass

1.53 g are suspended from a ﬁxed point by

three nonconducting threads, each with a

length of 56.4 cm and negligible mass. At

equilibrium the three balls form an equilateral triangle with sides of 31 cm.

What is the common charge carried by

each ball? The acceleration of gravity is

9.8 m/s

2

and the value of Coulomb’s constant

is 8.98755 × 10

9

N · m2

/C

2

.

Answer in units of µC