# Example 2.1  
 m1  =   1 kg
 a  =   9.75 m/s^2
 F1 = m1 * a ; N 

# Example 2.1E     
 m1  =   1 lbm
 a  =   32.0 ft /s^2
 F1 = m1 * a ; lbf

# Example 2.2     
 Vgranite   =   0.12 m^3
 Vsand   =   0.15 m^3
 Vwater   =   0.20 m^3
 Vair   =   0.53 m^3
 rgranite   =   2750 kg/m^3
 rsand   =   1500 kg/m^3
 rwater  =   997 kg/m^3
 rair   =   1.15 kg/m^3
 Vtotal = Vgranite + Vsand + Vwater + Vair  ; m^3 
 mgranite = rgranite  * Vgranite  ; kg 
 msand = rsand  * Vsand  ; kg 
 mwater = rwater  * Vwater  ; kg 
 mair = rair  * Vair   ; kg 
 mtotal = mgranite + msand + mwater + mair  ; kg 
 n = Vtotal / mtotal   ; m^3/kg 
 r = mtotal / Vtotal  ; kg/m^3 


# Example 2.3      
 Dcyl   =   0.10 m
 Drod   =   0.01 m
 m1   =   25.0 kg
 Patm   =   101 kPa
 Phyd   =   250 kPa
 Acyl = pi()  * Dcyl^2 / 4 ; mm^2 
 Arod = pi()  * Drod^2 / 4 ; mm^2 
 Frod = Phyd  * Acyl - Patm  * (Acyl - Arod) - m1 * grav() ; N 


# Example 2.4     
 rmerc   =   13590 kg/m^3
 H0   =   24.00 cm
 Habs   =   750.00 mm
 DP = rmerc  * grav()  * H0 ; kPa 
 Pabs = rmerc  * grav()  * Habs  ; kPa 
 Pvessel = Pabs + DP  ; atm


# Example 2.4E     
 rmerc  = 848.0 lbm / ft^3
 H0   =   9.50 in
 Habs   =   29.50 in
 DP = rmerc  * grav()  * H0 ; lbf/in^2 
 Pabs = rmerc  * grav()  * Habs  ; lbf/in^2 
 Pvessel = Pabs + DP  ; lbf/in^2 


# Example 2.5     
 rgas   =   750.0 kg/m^3
 H0   =   7.50 m
 Ptop   =   101.00 kPa
 DP = rgas  * grav()  * H0 ; kPa 
 Ptotal = Ptop + DP  ; kPa 


# Example 2.5      
 rrefridge   =   1206.0 kg/m^3
 H0   =   7.50 m
 Ptop   =   1.00 MPa
 DP = rrefridge  * grav()  * H0 ; kPa 
 Ptotal = Ptop + DP  ; kPa 

# Example 2.6      
 P0   =   100.0 kPa
 A1   =   0.01 m^2
 F1   =   25.00 kN
 A2   =   0.05 m^2
 H0   =   6.00 m
 r  =   900.0 kg/m^3
 P1 = P0 + F1 / A1  ; kPa 
 DP = r  * grav()  * H0 ; kPa 
 P2 = P1 - DP   ; kPa 
 F2 = (P2 - P0)  *  A2   ; kN 

# Homework Problems:

TBD