Suppose that the sound level of a conversation is initially at an angry 72 db and then drops to a soothing 53 db. assuming that the frequency of the sound is 522 hz, determine the (a) initial and (b) final sound intensities and the (c) initial and (d) final sound wave amplitudes. assume the speed of sound is 343 m/s and the air density is 1.21 kg/m3.

A47.2 g block of copper whose temperature is 480 k is placed in an insulating box with a 91.8 g block of lead whose temperature is 200 k. (a) what is the equilibrium temperature of the two-block system? (b) what is the change in the internal energy of the two-block system between the initial state and the equilibrium state? (c) what is the change in the entropy of the two-block system? the heat capacities of copper and lead are 386 j/kg·k and 128 j/kg·k, respectively.