import math #Example9_1
#To find its mass and how large a cube of ice has the same mass
pu=18680.0 #units in Kg/meter**3
s=2*10**-2 #units in meters
vu=s**3.0 #units in meter**3
mu=pu*vu #units in Kg
print "Mass Mu=",round(mu,3)," Kg\n"
pi=920 #units in Kg/meter**3
vi=mu/pi #units in meter**3
ss=vi**(1/3.0)*10**2 #units in cm
print "Side length of ice cube is=",round(ss,2),"cm"
import math #Example9_2
#To calculate the cross sectional area and how far the ball will stretch the wire
m=40.0 #units in Kg
g=9.8 #units in meter/sec**2
F=m*g #units in Kg meter/sec**2
stress=0.48*10**8 #units in Newton/meter**2
A=F/stress #units in meter**2
r=math.sqrt(A/math.pi)*10.0**3 #units in mm
print "The radius of the wire should be r=",round(r,1)," mm and the cross sectional area is A=",round(A),"meter**2"
y=200.0*10**9 #units in Newton/meter**2
strain=stress/y
L0=15 #units in meters
deltaL=strain*L0 #units in meters
deltaL=deltaL*10**3 #units in mm
print "\nThe ball stretches the wire a distance of deltaL=",round(deltaL,2),"mm"
import math #Example9_7
#To find out by what factor the blood flow in an artery is reduced
r1_r2=1/2.0 #The ratio by which the radius is altered in arterys
R1_R2=1/r1_r2**4 #Ratio by which flow is altered
print "The flow rate is reduced by a factor of ",round(R1_R2)
import math #Example9_9
#To compare the pressures at A and at B
p=1000 #Units in Kg/Meter**3
va=0.2 #units in meters/sec
vb=2 #units in meters/sec
Pa_Pb=-0.5*p*(va**2-vb**2) #units in Pa
print "Pressure Difference at A and B is Pa-Pb=",round(Pa_Pb)," Pa therefore Preasure at A is High than at B"
import math #Example9_10
#To find out how fast a raindrop becomes turbulent
Nr=10 #Number of molecules
n=1.9*10**-5 #Units in PI
p=1.29 #Units in Kg/Meter**3
d=3*10**-3 #Units in meters
vc=(Nr*n)/(p*d) #units in meters/sec
print "The speed of the rain drop is Vc=",round(vc,3)," meters/sec"
import math #Example9_11
#To find out what horsepower is required
p=1.29 #Units in Kg/Meter**3
Cd=0.45
af=2 #Units in Meter**2
v=20 #Units in meters/sec
M=1000 #units in Kg
F=(0.5*p*Cd*af*v**2)+((M/1000)*((110+(1.1*v)))) #Units in Newtons
Power=F*v #Units in Watts
Power=Power/747.3061 #units in Horse Power
reqHPower=Power**2 #unis in Horse power
print "The required power is=",round(reqHPower)," hp"
#In text book the answer is printed wrong as 80 Hp the correct answer is 95Hp
import math #Example9_12
#To find out the sedimentation rate of sphrical particles
b=2*10**-3 #units in cm
g=9.8 #Units in meters/sec**2
n=1 #units in m PI
Pp_Pt=1050 #units in Kg/Meter**3
vt=(((2*b**2*g)/(9*n))/(2*Pp_Pt))*10**6 #units in cm/sec
print "Sedimentation is vt=",round(vt,4),"cm/sec"
#in text book answer is printed wrong as vt=4.36*10**-3 cm/sec but the correct answer is vt=4.14*10**-3 cm/sec