In [1]:

```
#importing modules
import math
from __future__ import division
#Variable declaration
V=7500; #volume(m**3)
T=1.5; #time(sec)
#Calculations
aS=0.165*V/T; #total absorption in hall(OWU)
#Result
print "total absorption in hall is",aS,"OWU"
```

In [2]:

```
#importing modules
import math
from __future__ import division
#Variable declaration
V=1500; #volume(m**3)
A1=112; #area of plastered walls(m**2)
A2=130; #area of wooden floor(m**2)
A3=170; #area of plastered ceiling(m**2)
A4=20; #area of wooden door(m**2)
n=100; #number of cushioned chairs
A5=120; #area of audience(m**2)
C1=0.03; #coefficient of absorption in plastered walls
C2=0.06; #coefficient of absorption in wooden floor
C3=0.04; #coefficient of absorption in plastered ceiling
C4=0.06; #coefficient of absorption in wooden door
C5=1.0; #coefficient of absorption in cushioned chairs
C6=4.7; #coefficient of absorption in audience
#Calculations
a1=A1*C1; #absorption due to plastered walls
a2=A2*C2; #absorption due to wooden floor
a3=A3*C3; #absorption due to plastered ceiling
a4=A4*C4; #absorption due to wooden door
a5=n*C5; #absorption due to cushioned chairs
a6=A5*C6; #absorption due to audience
aS=a1+a2+a3+a4+a5; #total absorption in hall
T1=0.165*V/aS; #reverberation time when hall is empty(sec)
T2=0.165*V/(aS+a6); #reverberation time with full capacity of audience(sec)
T3=0.165*V/((n*C6)+aS); #reverberation time with audience in cushioned chairs(sec)
#Result
print "reverberation time when hall is empty is",round(T1,2),"sec"
print "reverberation time with full capacity of audience is",round(T2,3),"sec"
print "reverberation time with audience in cushioned chairs is",round(T3,2),"sec"
```

In [3]:

```
#importing modules
import math
from __future__ import division
#Variable declaration
V=1200; #volume(m**3)
a1=220; #area of wall(m**2)
a2=120; #area of floor(m**2)
a3=120; #area of ceiling(m**2)
C1=0.03; #coefficient of absorption in wall
C2=0.80; #coefficient of absorption in floor
C3=0.06; #coefficient of absorption in ceiling
#Calculations
A1=a1*C1; #absorption due to plastered walls
A2=a2*C2; #absorption due to wooden floor
A3=a3*C3; #absorption due to plastered ceiling
aS=a1+a2+a3; #total absorption in hall
abar=(A1+A2+A3)/aS; #average sound absorption coefficient
AS=abar*aS; #total absorption of room(metric sabines)
T=0.165*V/AS; #reverberation time(sec)
#Result
print "average sound absorption coefficient is",round(abar,2)
print "reverberation time is",round(T,1),"sec"
```

In [5]:

```
#importing modules
import math
from __future__ import division
#Variable declaration
I0=10**-12; #standard intensity level(watt/m**2)
A=1.4; #area(m**2)
il=60; #intensity level(decibels)
#Calculations
x=10**(il/10);
I=x*10**-12; #intensity level(watt/m**2)
Ap=I*A; #acoustic power(watt)
#Result
print "acoustic power is",Ap,"watt"
print "answer in the book is wrong"
```