Chapter 1 : Introduction

Example 1.1 page : 4

In [1]:
# Variables
F = 730.;       			#Force(N)
g_texas = 9.792;			#Acceleration of gravity in Houston,Texas(m/s**2).
g_moon = 1.67;	    		#Acceleration of gravity at moon(m/s**2).

# Calculations
m = round(F/g_texas,2);			#Mass of Astronaut(Kg)
F_moon = round(m*g_moon,2);			#Force on Moon(N)

# Results
print 'Mass of Astronaut',m, "Kg"
print 'Force on Moon',F_moon,'N'

Mass of Astronaut 74.55 Kg
Force on Moon 124.5 N

Example 1.3 page : 10

In [8]:
import math 

# Variables
d = 0.01			#Diameter(m)
m = 6.14			#Mass(Kg)
g = 9.82			#Acceleration of gravity
Pb = 748.			#Barometric Pressure(Torr)

# Calculations
F = round(m*g,3);			#Force(N)
A = (math.pi/4)*d*d;			#Area(m**2)
Pg = round(F/A,-2);			#Gauge Pressure(N/m**2)
Pa = round(Pg+(Pb*0.013332*(10**4)),-2);			#Absolute Pressure(Pa)

# Results
print 'Force ',F,'N'
print 'Gauge Pressure ',Pg/10**4,'(X 10**4) N/m**2'
print 'Absolute Pressure',Pa/1000,'KPa'

Force  60.295 N
Gauge Pressure  76.77 (X 10**4) N/m**2
Absolute Pressure 867.4 KPa

Example 1.4 page : 11

In [12]:
# Variables
T = 300.15;	    		#Temp = 300.15K(27`C)
h = 60.5*(10**-2);			#Height = 60.5cm
rho = 13530.;			#Density(Kg/m**3)
g = 9.784;		    	#Acceleration of gravity(m/s**2)

# Calculations
P = round(h*rho*g,0);

# Results
print 'Pressure in KPa %.2f'%(P/1000),'KPa'
print 'Pressure in bar %.4f'%(P/100000),'bar'

Pressure in KPa 80.09 KPa
Pressure in bar 0.8009 bar

Example 1.5 page : 16

In [13]:
import math 
from scipy.integrate import quad 

# Variables
M = 2500.;			#Mass = 2500Kg
h1 = 10.;			#height1 = 10m
h2 = 100.;			#height2 = 100m
g = 9.8;			#Acceleration of gravity(m/s**2)

# Calculations and Results
#(a)
PE1 = M*h1*g;			#[j]
print '(a)Potential energy of the elevator in its Initial Position',PE1,'J'

#(b)
def f0(l): 
    return 1

W = M*g* quad(f0,h1,h2)[0];			#[j][0]
print '(b)Work Done in Raimath.sing the Elevator',W,'J'

#(c)
PE2 = M*g*h2;			#[j]
print '(c)Potential energy of the elevator in its Highest Position',PE2,'J'

#(d)
KE2 = 0;
PE3 = 0;
KE3 = PE2;			#[j]   			#Conservation Of Mechanical Energy
u = round((2*KE3/M)**(1./2),2);			#(m/s)
print '(d)Velocity of the Elevator',u,'m/s'
print '(d)Kinetic Energy of the Elevator',KE3,'J'

#(e)
PE_Spring = KE3;			#[j]
print '(e)Potential energy of compressed spring ',PE_Spring,'J'

#(f)
TE = PE1+W;
print '(f)Total Energy of the System',TE,'J'

(a)Potential energy of the elevator in its Initial Position 245000.0 J
(b)Work Done in Raimath.sing the Elevator 2205000.0 J
(c)Potential energy of the elevator in its Highest Position 2450000.0 J
(d)Velocity of the Elevator 44.27 m/s
(d)Kinetic Energy of the Elevator 2450000.0 J
(e)Potential energy of compressed spring  2450000.0 J
(f)Total Energy of the System 2450000.0 J