James wants to lower the pitch coming from an electronic sound generator. how would he achieve that? a. he should increase the amplitude. b. he should increase the frequency c. he should decrease the amplitude. d. he should decrease the frequency. e. he should increase the intensity.

Adielectric-filled parallel-plate capacitor has plate area a = 30.0 cm2 , plate separation d = 9.00 mm and dielectric constant k = 3.00. the capacitor is connected to a battery that creates a constant voltage v = 15.0 v . throughout the problem, use ϵ0 = 8.85x10-12 c2/n.m2 . find the energy u1 of the dielectric-filled capacitor.