In [2]:

```
# Variables
t1 = 300; #temperature of the surroundings in K
t2 = 900; #temperature of the hot body p in K
t3 = 500; #temperature of the hot body q in K
a = 5.67*10**-8; #stefan boltzmann consmath.tant in W/m**2.K**4
# Calculations
q1 = a*(t2**4-t1**4); #heat lost from hot body p in w/m**2
q2 = a*(t3**4-t1**4); #heat lost from hot body q in w/m**2
q = q1/q2; #ratio of heat lost from two subsmath.tances
# Result
print 'ratio of heat lost from two substances is %3.1f/1'%(q)
```

In [4]:

```
# Variables
t1 = 573; #temperature of the hot side in K
t2 = 273; #temperature of the coll side in K
m = 82; #mass of the black body in gm
cp = 0.1; #specific heat of the black body kj/kg.K
dt = 0.35; #ice melting at a rate of temperature in deg.C/sec
a = 8; #area of black body in sq.cm
# Calculations
s = m*cp*dt/(a*(t1**4-t2**4)); #boltzmann constant in cal/sq.cm/sec/deg**4
# Result
print 'boltzmann consmath.tant is %.2e cal/sq.cm/sec/deg**4'%(s)
```

In [5]:

```
# Variables
r1 = 60.; #distance of first black body in cm
r2 = 30.; #distance of second black body in cm
t1 = 873.; #temperature of first black body in K
t2 = 573.; #temperature of the second black body in K
# Calculations
i = (t2**4/t1**4)*(r1**2/r2**2); #ratio of intensity of radition
# Result
print 'ratio of intensity of radition is %3.2f'%(i)
```

In [7]:

```
# Variables
t1 = 1373; #temperature of the sphere in K
t2 = 283; #temperature of the black body in K
r = 4.17*10**5; #rate of heat radiate in ergs/sq.cm/sec
a = 4*3.14*(6**2); #surface area of the sphere in sq.cm
tr = r*a*(t1**4/t2**4)*(2.39005736*10**(-8)); #total heat radiated in cal/sec
# Result
print 'total heat radiated is %3.1f cal/sec'%(tr)
```

In [8]:

```
# Variables
h = 2*3.14*100; #heat received by the lens per min in cal
m = 25.; #mass of the ice in gm
l = 80; #latent heat of ice in cal/gm
# Calculations
t = m*l/h; #time for which the sun rays falls in min
# Result
print 'time for which the sun rays falls is %3.3f min'%(t)
```

In [10]:

```
# Variables
d = 0.35; #diameter of the mirror in m
t = 5; #time in min
T = 16; #temperature of water found to be in deg.C
m = 60; #mass of water in gm
mc = 30; #mass of calorimeter in gm
cp = 0.1; #specific heat of copper in cal/gm/deg.C
# Calculations
q = (m+cp*mc)*T*4/(5*3.14*d**2); #amount of heat received by earth in cal
# Result
print 'amount of heat received by earth is %3.f cal'%(q)
```

In [16]:

```
# Variables
r1 = 5.; #radius of first sphere in cm
r2 = 10.; #radius of second sphere in cm
t1 = 700.; #temperature of the first sphere in K
t2 = 500.; #temperature of the second sphere in K
t = 300.; #temperature of the enclousure in K
# Calculations1
dc = (r2/r1)*(t1**4-t**4)/(t2**4-t**4); #ratio of c1/c2
r = r1**3*dc/r2**3; #rate of heat loss
# Result
print 'rate of loss of heat is %3.3f'%(r)
```

In [19]:

```
# Variables
t1 = 600.; #temperature of the black body in K
t0 = 300.; #temperature of the surroundings in K
d = 6.; #deflections in galvanometer
d1 = 400.; #deflection in divisions
# Calculations
dt = (d1/d)*(t1**4-t0**4); #change of temperature
t2 = (dt+t0**4)**(1./4); #end temperature in K
# Result
print 'end temperature of the temperature is %3.2f K'%(t2)
print "Note : answer in book in incorrect. Please calculate manually."
```

In [21]:

```
# Variables
n = 17000; #luminosity of star compared to sun
t = 6000; #temperature of the sun in K
# Calculations
t1 = (n*t**4)**(1./4); #temperature of the star in K
# Result
print 'the temperature of the star is %3.f K'%(round(t1,-1))
```