When a 109 db sound wave comes through an open window of area 0.485 m2, how much acoustic energy passes through the window in a 10.9 min interval?

57dB

Explanation:

two charges are fixed in place on the x-axis as shown. the charge at x = 0 is negative and has magnitude q = 2 μcoulombs (1 μcoulomb = 10-6 coulombs). the charge at x = d, (d = +12 cm), is positive and has magnitude q = 4 μcoulombs. find a point x = xo along the x-axis at which the electric field is zero.