Chapter 9 :Heat¶

Example 9.2 , Page no:52¶

In [1]:
import math
from __future__ import division

#initialisation of variables
tf=80; #temp in farenheit

#CALCULATIONS
tc=(5/9)*(tf-32); #calculating temp in celcius

#RESULTS
print"Temperature in celcius =",round(tc,3);

Temperature in celcius = 26.667


Example 9.3 , Page no:52¶

In [2]:
import math
from __future__ import division

#initialisation of variables
tc=80; #/temp in celcius

#CALCULATIONS
tf=((9/5)*tc)+32; #calculating temp in farenheit

#RESULTS
print"Temperature in farenheit =",round(tf,3);

Temperature in farenheit = 176.0


Example 9.4 , Page no:52¶

In [3]:
import math
from __future__ import division

#initialisation of variables
tf=-362; #temp in farenheit

#CALCULATIONS
tc=(5/9)*(tf-32); #calculating temp in celcius

#RESULTS
print"Temperature in celcius =",round(tc,3);

Temperature in celcius = -218.889


Example 9.5 , Page no:52¶

In [4]:
import math
from __future__ import division

#initialisation of variables
tc=-210; #temp in celcius

#CALCULATIONS
tf=((9/5)*tc)+32; #calculating temp in farenheit

#RESULTS
print"Temperature in farenheit =",round(tf,3);

Temperature in farenheit = -346.0


Example 9.6 , Page no:52¶

In [5]:
import math
from __future__ import division

#initialisation of variables
delt=80-20; #change in temp in celcius
m=3; #mass in lb
c=4185; #specific heat in J/kg.celcius

#CALCULATIONS
Q=m*c*delt; #calculating heat required

#RESULTS
print"Heat required in Joule =",round(Q,3);

Heat required in Joule = 753300.0


Example 9.7 , Page no:53¶

In [6]:
import math
from __future__ import division

#initialisation of variables
Q=200; #heat in Btu(British Thermal Unit)
m=50; #mass in lb
c=0.5; #specific heat capacity inBtu/lb.F

#CALCULATIONS
delT=Q/(m*c); #calculating change in temperatur using Q=mc(del T)
delT1=25-delT;

#RESULTS
print"Change in Temperature in Farenheit =",round(delT,3);
print"Final Temperature in Farenheit =",round(delT1,3);

Change in Temperature in Farenheit = 8.0
Final Temperature in Farenheit = 17.0


Example 9.8 , Page no:53¶

In [7]:
import math
from __future__ import division

#initialisation of variables
Q=10; #Heat in kilo calorie
m=1; #mass in kg
delT=24; #change in temperature in degree celcius

#CALCULATIONS
c=Q/(m*delT); #calculating specific heat in kcal/(kg.degree celcius)

#RESULTS
print"Spacific Heat in kcal/(kg.degree celcius) =",round(c,3);

Spacific Heat in kcal/(kg.degree celcius) = 0.417


Example 9.9 , Page no:53¶

In [8]:
import math
from __future__ import division

#initialisation of variables
t=500/8; #using heat gained = heat lost

#RESULTS
print"Final temperature in Farenheit =",round(t,3);

Final temperature in Farenheit = 62.5


Example 9.10 , Page no:53¶

In [9]:
import math
from __future__ import division

#initialisation of variables
t=(225990+3360)/2769; #calculating temperature

#RESULTS
print"Temperature in celcius =",round(t,3);

Temperature in celcius = 82.828


Example 9.11 , Page no:53¶

In [10]:
import math
from __future__ import division

#initialisation of variables
t=56.6/0.22; #calculating temperature

#RESULTS
print"Temperature in celcius =",round(t,3);

Temperature in celcius = 257.273


Example 9.12 , Page no:54¶

In [11]:
import math
from __future__ import division

#initialisation of variables
delT=626-70; #change in temp. in Farenheit
m=200; #mass in lb
c=0.03; #specific heat capacity in Btu/(lb.Farenheit)
Lf=10.6; #Latent Heat of Fusion in Btu/lb

#CALCULATIONS
Q=(m*c*delT)+(m*Lf); #calculating heat in Btu

#RESULTS
print"Heat Required in Btu =",round(Q);

Heat Required in Btu = 5456.0


Example 9.13 , Page no:54¶

In [12]:
import math
from __future__ import division

#initialisation of variables
mw=5; #mass of water in kg
c=1; #specific heat of water in kcal/(kg.degree celcius)
delT=40; #change in temp in celcius
Lf=80; #Latent heat of Fusion in kcal/kg

#CALCULATIONS
mice=(mw*c*delT)/Lf; #calculating mass of ice in kg

#RESULTS
print"Mass of Ice in kg =",round(mice,3);

Mass of Ice in kg = 2.5


Example 9.14 , Page no:54¶

In [13]:
import math
from __future__ import division

#initialisation of variables
m1=2; #mass of water in kg
c=1; #specific heat in kcal/kg.celcius
delT=20; #change in temp. in celcius
L=540; #L in kcal/kg

#CALCULATIONS
Q1=m1*c*delT; #calculating heat in kcal
Q2=500-Q1; #calculating heat available to convert water at 100 celcius to steam
msteam=Q2/L; #calculating mass of steam in kg

#RESULTS
print"Steam produced in kg =",round(msteam,3);

Steam produced in kg = 0.852


Example 9.15 , Page no:54¶

In [14]:
import math
from __future__ import division

#initialisation of variables
deltice=10; #change in temp of ice in celcius
deltwater=20; #change in temp of water in celcius
mwater=0.5; #mass of water in kg
cwater=4.185; #specific heat of water in kJ/kg.celcius
Lice=335; #latent heat in kJ/kg
cice=2.09; #specific heat of ice in kJ/kg.celcius

#CALCULATIONS
mice=(mwater*cwater*deltwater)/((cice*deltice)+Lice);
mice1=mice*1000;

#RESULTS
print"Minimum amount of ice in gram =",round(mice1,3);

Minimum amount of ice in gram = 117.589


Example 9.18 , Page no:55¶

In [15]:
import math
from __future__ import division

#initialisation of variables
g=9.8; #gravitational constant in m/sec square
Lf=3.35*10**5; #Latent heat of fusion in J/kg

#CALCULATIONS
h=Lf/g; #calculating height in metre using potential energy(m*g*h)=(mass*heat of fusion)

#RESULTS
print"Height of falling in metre =",round(h,3);

Height of falling in metre = 34183.673


Example 9.19 , Page no:55¶

In [16]:
import math
from __future__ import division

#initialisation of variables
m=0.8; #mass of water in kg
c=4185; #specific heat in J/kg.celcius
delT=100-20; #change in temperature in celcius
P=10**3; #Power in J/sec

#CALCULATIONS
Q=m*c*delT; #calculating heat required in Joule
t=Q/P; #calculating time using P=(Q/t)
t1=t/60;

#RESULTS
print"Time required to raise temperature to 100 degree celcius in second =",round(t,3);
print"Time in minutes =",round(t1,3);

Time required to raise temperature to 100 degree celcius in second = 267.84
Time in minutes = 4.464