In [1]:

```
# Input data
l = 1. # The thickness of the crystal in cm
w = 5890. - 8 # The wavelength of light used in cm
t2 = 50. # The final temperature of the crystal in degree centigrade
t1 = 20. # The initial temperature of the crystal in degree centigrade
p = 14. # The number of fringes that crossed the field of view
# Calculations
t = t2 - t1 # The temperature difference in degree centigrade
# The coefficient of linear expansion of the crystal in per degree centigrade
a = (p * w) / (2 * l * t)
# output
print 'The coefficient of linear expansion of the crystal is %3.4g degree centigrade' % (a)
```

In [2]:

```
# Input data
L = 500. # The length of a steel rod in cm
t = 40. # The increase in temperature in degree centigrade
y = 2. * 10**12 # The youngs modulus of elasticity of steel in dynes/cm**2
e = 12. * 10**-6 # The coefficient of linear expansion of steel in per degree centigrade
# Calculations
S = y * e * t # The stress in the rod in dynes/cm**2
# Output
print 'The stress in the rod is %3g dynes/cm^2' % (S)
```

In [3]:

```
# Input data
L = 800. # The length of the wire in cm
r = 0.2 # The radius of the wire in cm
t = 10. # The temperature fall in degree centigrade
a = 12. * 10**-6 # The coefficient of linear expansion of steel wire in per degree centigrade
y = 2. * 10**12 # The youngs modulus of elasticity of steel in dynes/cm**2
pi = (22. / 7) # Mathematical constant pi
# Calculations
I = y * a * t * pi * r**2 # The increase in tension in dynes
# Output
print 'The increase in tension is %3g dynes' % (I)
```

In [5]:

```
# Input data
A = 2. * 10**-6 # The cross section area of a uniform rod in m**2
t = 20. # The change in temperature in degree centigrade
y = 10.**11 # The youngs modulus of the rod in newtons/m**2
a = 12. * 10**-6 # The coefficient of linear expansion of rod in per degree centigrade
# Calculations
F = y * a * t * A # The force required to prevent it from expanding in newtons
E = (1. / 2) * y * a * t * a * t # The energy stored per unit volume in j/m**3
# Output
print 'The force required to prevent the rod from expanding is %3.0f newtons \
\nThe Energy stored per unit volume is %3.0f j/m^3' % (F, E)
```

In [6]:

```
# Input data
d = 10.**-3 # The diameter of a steel wire in m
t = 20. # The difference in the temperature in degree centigrade
y = 2. * 10**11 # The youngs modulus of a steel wire in newtons/m**2
a = 12. * 10**-6 # The coefficient of linear expansion of steel wire in per degree centigrade
pi = (22. / 7) # Mathematical constant value
# calculations
A = (pi * d**2) / 4 # The cross sectional area of the steel wire in m**2
# Force required to maintain the original length in kg wt
F = (y * a * t * A) / (9.8)
# output
print 'Force required to maintain the original length is %3.3f kg wt ' % (F)
```