diff options
Diffstat (limited to '3886/CH6')
36 files changed, 362 insertions, 0 deletions
diff --git a/3886/CH6/EX6.1/6_1.sce b/3886/CH6/EX6.1/6_1.sce new file mode 100644 index 000000000..b7c7723be --- /dev/null +++ b/3886/CH6/EX6.1/6_1.sce @@ -0,0 +1,30 @@ +//Determine velocity ratio,mechanical advantage,efficiency,ideal effort,effort lost in friction,ideal load and frictional resistance.
+ W=10000 //N
+P=500 //N
+//distance moved by effort
+D=20 //m
+d=0.8 //m
+//mechanical advantage
+MA=W/P
+printf("\nMechanical advantage=%0.1d",MA)
+//Velocity ratio
+VR=D/d
+printf("\nVelocity ratio=%0.1d",VR)
+//efficiency
+e=MA*100/VR //percent
+printf("\nEfficiency=%0.1d percent",e)
+//ideal effort
+Pi=W/VR //N
+printf("\nIdeal effort=%0.1d N",Pi)
+//Effort lost in friction
+E=P-Pi //N
+printf("\nEffort lost in friction=%0.1d N",E)
+//Ideal load
+Wi=P*VR //N
+printf("\nIdeal load=%0.1d N",Wi)
+//Frictional resistance
+F=Wi-W //N
+printf("\nFrictional resistance=%0.1d N",F)
+
+
+
diff --git a/3886/CH6/EX6.1/6_1.txt b/3886/CH6/EX6.1/6_1.txt new file mode 100644 index 000000000..ff6ae3971 --- /dev/null +++ b/3886/CH6/EX6.1/6_1.txt @@ -0,0 +1,10 @@ +
+--> exec('E:\My program EM\6. Lifting machines\6.1.sce', -1)
+
+Mechanical advantage=20
+Velocity ratio=25
+Efficiency=80 percent
+Ideal effort=400 N
+Effort lost in friction=100 N
+Ideal load=12500 N
+Frictional resistance=2500 N
\ No newline at end of file diff --git a/3886/CH6/EX6.10/6_10.sce b/3886/CH6/EX6.10/6_10.sce new file mode 100644 index 000000000..ec227cc59 --- /dev/null +++ b/3886/CH6/EX6.10/6_10.sce @@ -0,0 +1,10 @@ +//Force P required to raise the load
+eta=0.70
+W=2500 //N
+//refer fig. 6.17
+//For third order pulley
+//VR=2^2-1
+//For whole system
+VR=3+3
+P=W/(eta*VR) //N
+printf("Required force p=%.2f N",P)
diff --git a/3886/CH6/EX6.10/6_10.txt b/3886/CH6/EX6.10/6_10.txt new file mode 100644 index 000000000..0ed081241 --- /dev/null +++ b/3886/CH6/EX6.10/6_10.txt @@ -0,0 +1,3 @@ +
+--> exec('E:\My program EM\6. Lifting machines\6.10.sce', -1)
+Required force p=595.24 N
\ No newline at end of file diff --git a/3886/CH6/EX6.11/6_11.sce b/3886/CH6/EX6.11/6_11.sce new file mode 100644 index 000000000..b634f8953 --- /dev/null +++ b/3886/CH6/EX6.11/6_11.sce @@ -0,0 +1,12 @@ +//find necessary effort
+//effective wheel diameter
+D=(6/2)+500+(6/2) //mm
+//effective axle diameter
+d=(20/2)+200+(20/2) //mm
+VR=D/d
+eta=0.7
+MA=eta*VR
+W=1200
+P=1200/1.63 //N
+printf("The effort necessary=%.2f N",P)
+
diff --git a/3886/CH6/EX6.11/6_11.txt b/3886/CH6/EX6.11/6_11.txt new file mode 100644 index 000000000..22130f44a --- /dev/null +++ b/3886/CH6/EX6.11/6_11.txt @@ -0,0 +1,3 @@ +
+--> exec('E:\My program EM\6. Lifting machines\6.11.sce', -1)
+The effort necessary=736.20 N
\ No newline at end of file diff --git a/3886/CH6/EX6.12/6_12.sce b/3886/CH6/EX6.12/6_12.sce new file mode 100644 index 000000000..99d51ca1a --- /dev/null +++ b/3886/CH6/EX6.12/6_12.sce @@ -0,0 +1,13 @@ +//required effort
+//differential axle diameters
+d1=300 //mm
+d2=250 //mm
+//wheel diameter
+D=800 //mm
+//load
+W=20000 //N
+eta=0.55
+VR=(2*D)/(d2-d1)
+MA=eta*VR
+P=W/MA //N
+printf("Required effort =%0.1f N",-P)
diff --git a/3886/CH6/EX6.12/6_12.txt b/3886/CH6/EX6.12/6_12.txt new file mode 100644 index 000000000..b63f00a2c --- /dev/null +++ b/3886/CH6/EX6.12/6_12.txt @@ -0,0 +1,3 @@ +
+--> exec('E:\My program EM\6. Lifting machines\6.12.sce', -1)
+Required effort =1136.4 N
\ No newline at end of file diff --git a/3886/CH6/EX6.13/6_13.sce b/3886/CH6/EX6.13/6_13.sce new file mode 100644 index 000000000..cf0b07d40 --- /dev/null +++ b/3886/CH6/EX6.13/6_13.sce @@ -0,0 +1,9 @@ +//Effort required
+D=500 //mm
+d=200 //mm
+W=5000 //N
+eta=0.6
+VR=2*D/(D-d)
+MA=eta*VR
+P=W/MA //N
+printf("Required effort=%0.0f N",P)
diff --git a/3886/CH6/EX6.13/6_13.txt b/3886/CH6/EX6.13/6_13.txt new file mode 100644 index 000000000..53c390b01 --- /dev/null +++ b/3886/CH6/EX6.13/6_13.txt @@ -0,0 +1,3 @@ +
+--> exec('E:\My program EM\6. Lifting machines\6.13.sce', -1)
+Required effort=2500 N
\ No newline at end of file diff --git a/3886/CH6/EX6.14/6_14.sce b/3886/CH6/EX6.14/6_14.sce new file mode 100644 index 000000000..68df5a803 --- /dev/null +++ b/3886/CH6/EX6.14/6_14.sce @@ -0,0 +1,9 @@ +//Force required at the end of lever
+d=40 //mm
+p=20/3 //mm
+W=40000 //N
+R=400 //mm
+mu=0.12
+theta=atand(p/(%pi*d)) //degree
+P=(d*W*(mu+tand(theta)))/(2*R*(1-mu*tand(theta))) //N
+printf("Force required at the end of lever P=%0.2f N",P)
diff --git a/3886/CH6/EX6.14/6_14.txt b/3886/CH6/EX6.14/6_14.txt new file mode 100644 index 000000000..9f6d51f2d --- /dev/null +++ b/3886/CH6/EX6.14/6_14.txt @@ -0,0 +1,3 @@ +
+--> exec('E:\My program EM\6. Lifting machines\6.14.sce', -1)
+Force required at the end of lever P=348.32 N
\ No newline at end of file diff --git a/3886/CH6/EX6.15/6_15.sce b/3886/CH6/EX6.15/6_15.sce new file mode 100644 index 000000000..7cae55cb3 --- /dev/null +++ b/3886/CH6/EX6.15/6_15.sce @@ -0,0 +1,14 @@ +//Screw jack parameters
+p=10 //mm
+d=50 //mm
+W=6000 //N
+theta=atand(p/(%pi*d)) //degree
+fi=atand(0.05) //degree
+R=300 //mm
+P=(d*W*tand(theta+fi))/(2*R) //N
+VR=(2*%pi*R)/(p)
+MA=W/P
+eta=MA*100/VR //percent
+//torque required to keep the load from descending
+T=(50*600*tand(3.6426-2.8624))/2 //N-mm
+printf("Efficiency eta=%0.2f percent > 50 percent\nThus the screw jack is not self locking\nTorque required to keep the load from descending T=%0.2f N-mm",eta,T)
diff --git a/3886/CH6/EX6.15/6_15.txt b/3886/CH6/EX6.15/6_15.txt new file mode 100644 index 000000000..cf1d0456e --- /dev/null +++ b/3886/CH6/EX6.15/6_15.txt @@ -0,0 +1,5 @@ +
+--> exec('E:\My program EM\6. Lifting machines\6.15.sce', -1)
+Efficiency eta=55.83 percent > 50 percent
+Thus the screw jack is not self locking
+Torque required to keep the load from descending T=204.27 N-mm
\ No newline at end of file diff --git a/3886/CH6/EX6.16/6_16.sce b/3886/CH6/EX6.16/6_16.sce new file mode 100644 index 000000000..8ad8da192 --- /dev/null +++ b/3886/CH6/EX6.16/6_16.sce @@ -0,0 +1,20 @@ +//Differential screw jack
+//pitch
+pA=10 //mm
+pB=5 //mm
+//lever arm length
+R=500 //mm
+VR=(2*%pi*R)/(pA-pB)
+P=185 //N
+W=15000 //N
+MA=W/P
+eta=MA*100/VR //percent
+//let the law of machine be P=m*W+C
+//from first case 185=m*15000+C
+//from second case 585=m*50000+C
+//solving we get
+m=4/350
+C=185-(m*15000) //N
+printf("Law of machine is P=%.4f*W+%0.2d ",m,C)
+
+
diff --git a/3886/CH6/EX6.16/6_16.txt b/3886/CH6/EX6.16/6_16.txt new file mode 100644 index 000000000..b8a1bd5fa --- /dev/null +++ b/3886/CH6/EX6.16/6_16.txt @@ -0,0 +1,3 @@ +
+--> exec('E:\My program EM\6. Lifting machines\6.16.sce', -1)
+Law of machine is P=0.0114*W+13
\ No newline at end of file diff --git a/3886/CH6/EX6.17/6_17.sce b/3886/CH6/EX6.17/6_17.sce new file mode 100644 index 000000000..278da7947 --- /dev/null +++ b/3886/CH6/EX6.17/6_17.sce @@ -0,0 +1,23 @@ +//single purchase crab
+//load drum radius
+r=200/2 //mm
+//Length of lever arm
+R=1200 //mm
+T2=100
+T1=10
+VR=(R*T2)/(r*T1)
+//let the law of machine be P=m*W+C
+//in first case 100=m*3000+C
+//in second case 160=m*9000+C
+//solving we get
+m=1/100
+C=70
+//P=0.01*W+70
+//case 1
+MA1=3000/100
+eta1=MA1*100/VR //percent
+//case 2
+MA2=9000/160
+eta2=MA2*100/VR //percent
+printf("\nVR=%.0f\nP=0.01*W+70\nIn first case\neta=%0.2f percent\nIn second case\neta=%0.2f percent",VR,eta1,eta2)
+
diff --git a/3886/CH6/EX6.17/6_17.txt b/3886/CH6/EX6.17/6_17.txt new file mode 100644 index 000000000..525c39114 --- /dev/null +++ b/3886/CH6/EX6.17/6_17.txt @@ -0,0 +1,9 @@ +
+--> exec('E:\My program EM\6. Lifting machines\6.17.sce', -1)
+
+VR=120
+P=0.01*W+70
+In first case
+eta=25.00 percent
+In second case
+eta=46.88 percent
\ No newline at end of file diff --git a/3886/CH6/EX6.18/6_18.sce b/3886/CH6/EX6.18/6_18.sce new file mode 100644 index 000000000..20eb30d16 --- /dev/null +++ b/3886/CH6/EX6.18/6_18.sce @@ -0,0 +1,12 @@ +//Double purchase crab
+T1=15
+T2=45
+T3=20
+T4=40
+R=400 //mm
+r=150/2 //mm
+VR=(R*T2*T4)/(r*T1*T3)
+eta=0.40
+MA=eta*VR
+W=12.8*250 //N
+printf("Applied load lifts a load of W=%.2f N",W)
diff --git a/3886/CH6/EX6.18/6_18.txt b/3886/CH6/EX6.18/6_18.txt new file mode 100644 index 000000000..52a5ba095 --- /dev/null +++ b/3886/CH6/EX6.18/6_18.txt @@ -0,0 +1,3 @@ +
+--> exec('E:\My program EM\6. Lifting machines\6.18.sce', -1)
+Applied load lifts a load of W=3200.00 N
\ No newline at end of file diff --git a/3886/CH6/EX6.2/6_2.sce b/3886/CH6/EX6.2/6_2.sce new file mode 100644 index 000000000..a8757768d --- /dev/null +++ b/3886/CH6/EX6.2/6_2.sce @@ -0,0 +1,18 @@ +//Simple machine
+//assume law of machine P=m*W+C
+//From first and second conditions we obtain 2 equations
+//150=2400*m+C
+//180=3000*m+C
+//upon solving them
+//P=0.05*W+30
+//When force of 200 N is applied
+W=(200-30)/(0.05) //N
+//Ideal effort
+Pi=3400/30 //N
+//Effort wasted in overcoming the friction
+Ew=200-113.33 //N
+//Mechanical advantage
+MA=3400/200
+//Efficiency
+Eff=(17*100)/(30) //percent
+printf("\n Law of machining is P=0.05*W+30\nW=%.2f N\nEffort wasted in overcoming the friction=%.2f N\nMechanical advantage=%.2f \nEfficiency=%.2f percent",W,Ew,MA,Eff)
diff --git a/3886/CH6/EX6.2/6_2.txt b/3886/CH6/EX6.2/6_2.txt new file mode 100644 index 000000000..44a9fe1a0 --- /dev/null +++ b/3886/CH6/EX6.2/6_2.txt @@ -0,0 +1,8 @@ +
+--> exec('E:\My program EM\6. Lifting machines\6.2.sce', -1)
+
+ Law of machining is P=0.05*W+30
+W=3400.00 N
+Effort wasted in overcoming the friction=86.67 N
+Mechanical advantage=17.00
+Efficiency=56.67 percent
\ No newline at end of file diff --git a/3886/CH6/EX6.3/6_3.sce b/3886/CH6/EX6.3/6_3.sce new file mode 100644 index 000000000..38e8349f4 --- /dev/null +++ b/3886/CH6/EX6.3/6_3.sce @@ -0,0 +1,23 @@ +//maximum mechanical advantage and maximum efficiency
+//Effort
+P=150 //N
+W=7700 //N
+MA=W/P //mechanical advantage
+//If efficiency=60%
+eff=0.6
+VR=(MA)/(eff)
+//When an effort of 250 N raised a load of 13200 N
+P1=250 //N
+W1=13200 //N
+MA1=(W1)/(P1)
+eff1=MA1*100/VR //percent
+//assume law of machine as P=m*W+C
+//from first case 150=7700*m+C
+//from second case 250=13200*m+C
+//Solving we get
+m=100/5500
+//maximum mechanical advantage
+MAmax=1/(m)
+//maximum efficiency
+Effmax=100/(m*VR) //percent
+printf("\nMechanical advantage=%0.2f\nVelocity ratio=%0.2f\nEfficiency=%0.2f percent\nMaximum mechanical advantage=%0.2f\nMaxumum efficiency=%0.2f percent",MA,VR,eff1,MAmax,Effmax)
diff --git a/3886/CH6/EX6.3/6_3.txt b/3886/CH6/EX6.3/6_3.txt new file mode 100644 index 000000000..2cb8e6833 --- /dev/null +++ b/3886/CH6/EX6.3/6_3.txt @@ -0,0 +1,8 @@ +
+--> exec('E:\My program EM\6. Lifting machines\6.3.sce', -1)
+
+Mechanical advantage=51.33
+Velocity ratio=85.56
+Efficiency=61.71 percent
+Maximum mechanical advantage=55.00
+Maxumum efficiency=64.29 percent
\ No newline at end of file diff --git a/3886/CH6/EX6.4/6_4.sce b/3886/CH6/EX6.4/6_4.sce new file mode 100644 index 000000000..5d11d01d4 --- /dev/null +++ b/3886/CH6/EX6.4/6_4.sce @@ -0,0 +1,21 @@ +//determine law of machine and maximum efficiency
+//fig.6.4 shows graph of effort vs load
+//from graph
+C=10 //N
+//slope
+m=30/500
+//Law of machine is P=m*W+C
+//P=0.06*W+10
+//eta=MA/VR=W/25P
+//table 6.5 shows calculation of efficiency for various loads
+//Refer fig. 6.5
+//from graph it can be seen that maximum efficiency=50% but the graph is plotted for infinitely large load
+//thus
+//Maximum efficiency
+VR=25
+Emax=100/(m*VR) //percent
+printf("\nLaw of machines is P=0.06*W+10\nMaximum efficiency=%.2f percent",Emax)
+
+
+
+
diff --git a/3886/CH6/EX6.4/6_4.txt b/3886/CH6/EX6.4/6_4.txt new file mode 100644 index 000000000..ebfbdbeb5 --- /dev/null +++ b/3886/CH6/EX6.4/6_4.txt @@ -0,0 +1,5 @@ +
+--> exec('E:\My program EM\6. Lifting machines\6.4.sce', -1)
+
+Law of machines is P=0.06*W+10
+Maximum efficiency=66.67 percent
\ No newline at end of file diff --git a/3886/CH6/EX6.5/6_5.sce b/3886/CH6/EX6.5/6_5.sce new file mode 100644 index 000000000..d21562520 --- /dev/null +++ b/3886/CH6/EX6.5/6_5.sce @@ -0,0 +1,13 @@ +//Lifting machine
+VR=30
+W=5000 //N
+P=360 //N
+MA=W/P
+//efficiency
+eta=MA*100/VR //percent
+printf("Since the efficiency eta=%0.2d percent is less than 50 percent,it is a self locking machine",eta)
+//ideal load
+Wi=P*VR //N
+//Frictional resistance
+FR=Wi-W //N
+printf("\nIdeal load=%0.2d N\nFrictional resistance=%0.2d N",Wi,FR)
diff --git a/3886/CH6/EX6.5/6_5.txt b/3886/CH6/EX6.5/6_5.txt new file mode 100644 index 000000000..b26205998 --- /dev/null +++ b/3886/CH6/EX6.5/6_5.txt @@ -0,0 +1,5 @@ +
+--> exec('E:\My program EM\6. Lifting machines\6.5.sce', -1)
+Since the efficiency eta=46 percent is less than 50 percent,it is a self locking machine
+Ideal load=10800 N
+Frictional resistance=5800 N
\ No newline at end of file diff --git a/3886/CH6/EX6.6/6_6.sce b/3886/CH6/EX6.6/6_6.sce new file mode 100644 index 000000000..5abfc27d7 --- /dev/null +++ b/3886/CH6/EX6.6/6_6.sce @@ -0,0 +1,16 @@ +//Finding the additional pulleys required
+//if n is number of movable pulleys then
+n=3
+VR=2^n
+eta=0.8
+MA=eta*VR
+P=6000/6.4 //N
+//In second case
+Effort=520 //N
+//efficiency eta=0.80-n1*0.05
+//n1=number of additional pulleys required=(n-3)
+//thus
+//W=P[0.8-(n-3)*0.05]*2^n
+//by using trial and erroe method
+nfinal=4
+printf("Number of movable pulleys required=%.0f",nfinal)
diff --git a/3886/CH6/EX6.6/6_6.txt b/3886/CH6/EX6.6/6_6.txt new file mode 100644 index 000000000..aee6fb38d --- /dev/null +++ b/3886/CH6/EX6.6/6_6.txt @@ -0,0 +1,3 @@ +
+--> exec('E:\My program EM\6. Lifting machines\6.6.sce', -1)
+Number of movable pulleys required=4
\ No newline at end of file diff --git a/3886/CH6/EX6.7/6_7.sce b/3886/CH6/EX6.7/6_7.sce new file mode 100644 index 000000000..85c5d0c8a --- /dev/null +++ b/3886/CH6/EX6.7/6_7.sce @@ -0,0 +1,9 @@ +//calculate force required
+//refer fig.6.15
+//VR=2*number of movable pulleys
+VR=2*3
+eta=0.85
+MA=eta*VR
+W=12000
+P=W/5.1
+printf("The required force is P=%.2f N",P)
diff --git a/3886/CH6/EX6.7/6_7.txt b/3886/CH6/EX6.7/6_7.txt new file mode 100644 index 000000000..8e6ae6399 --- /dev/null +++ b/3886/CH6/EX6.7/6_7.txt @@ -0,0 +1,3 @@ +
+--> exec('E:\My program EM\6. Lifting machines\6.7.sce', -1)
+The required force is P=2352.94 N
\ No newline at end of file diff --git a/3886/CH6/EX6.8/6_8.sce b/3886/CH6/EX6.8/6_8.sce new file mode 100644 index 000000000..6bac961d9 --- /dev/null +++ b/3886/CH6/EX6.8/6_8.sce @@ -0,0 +1,13 @@ +//Pull required
+//Refer fig.6.16
+//Let weight W be lifted by a distance x
+//Consider first order system
+//VR=2^2
+//Consider second order system
+VR=8
+eta=0.78
+MA=eta*VR
+W=12000
+P=W/6.24 //N
+printf("Required pull P=%0.2f N",P)
+
diff --git a/3886/CH6/EX6.8/6_8.txt b/3886/CH6/EX6.8/6_8.txt new file mode 100644 index 000000000..06a8c5c6e --- /dev/null +++ b/3886/CH6/EX6.8/6_8.txt @@ -0,0 +1,3 @@ +
+--> exec('E:\My program EM\6. Lifting machines\6.8.sce', -1)
+Required pull P=1923.08 N
\ No newline at end of file diff --git a/3886/CH6/EX6.9/6_9.sce b/3886/CH6/EX6.9/6_9.sce new file mode 100644 index 000000000..e231e7bed --- /dev/null +++ b/3886/CH6/EX6.9/6_9.sce @@ -0,0 +1,13 @@ +//machine efficiency and effort lost in friction
+//For third order system of pulleys
+W=1000
+VR=(2^3)-1
+eta=(1000*100)/(180*7) //percent
+//ideal effort
+Pi=(W)/(VR) //N
+P=180 //N
+//effort lost in friction
+Pl=P-Pi //N
+printf("Efficiency=%.2f percent\nEffort lost in friction=%.2f N",eta,Pl)
+
+
diff --git a/3886/CH6/EX6.9/6_9.txt b/3886/CH6/EX6.9/6_9.txt new file mode 100644 index 000000000..320e971d9 --- /dev/null +++ b/3886/CH6/EX6.9/6_9.txt @@ -0,0 +1,4 @@ +
+--> exec('E:\My program EM\6. Lifting machines\6.9.sce', -1)
+Efficiency=79.37 percent
+Effort lost in friction=37.14 N
\ No newline at end of file |