Question about pressure waves (vmax, deltaP)

[vande060]

Homework Statement

an isotropic sound source 5m away from you, of loudness is
50 dB. The speed of sound is 341.6 m/s , atmospheric pressure is 1.01 × 105 Pa and its density is
1.2 kg/m3

What is the maximum speed with which the air molecules move, due to the
passage of the wave?

and

What is the pressure amplitude of the accompanying pressure wave? (com-
pute the largest pressure deviation from atmospheric pressure caused by the wave) .

Homework Equations

I = 1/2pvvmax^2
I = 1/2*deltaP^2/pv

The Attempt at a Solution

okay so the first one seems pretty clear on the plug ins:

I = 1/2pvvmax^2

(I*1/2*341.6*1.2)^1/2 = vmax

I guess its the same for the second

I = 1/2*deltaP^2/pv
(I * 1/2*1.2*341.6)^1/2 = deltaP


this question can pretty much be distilled down to:

how can i calculate I with the given information?

 

[nilesh_pat]

I guess I could use the loudness equation, but I don't think that's the intent here.Loudness = 10 log(I/Io)Io = 10-12 W/m^2so I = 10^((50-12)/10) = 10^3.8 W/m^2vmax = (10^3.8*1/2*341.6*1.2)^1/2 deltaP = (10^3.8*1/2*1.2*341.6)^1/2 is this correct?