[填空题]
A large electroscope is made with “l / ho.8yxceb+ql z+zs7eaves” that are 78-cm-long w,m)uiwx zz 70zires with tiny 24-g spheres at the ends.izwzu , )zm7x0 When charged, nearly all the charge resides on the spheres. If the wires each make a $30^{\circ}$ angle with the vertical (Fig. 16–64), what total charge Q must have been applied to the electroscope? Ignore the mass of the wires. $ \times10^{-6 }\,CC$
