1. Questions & Answers Eng. Islam Al-Jarrah

2. 1 1211 10987 23 456 18 17 16151413 Eng. Islam Al-Jarrah

3.  A is twice the large of B, Specify direction and speed  If A rotates once then B will rotate ……….. Answer Eng. Islam Al-Jarrah

4.  A is twice the size of B.  What is the speed, direction and number of turns for B if A is the Driver. Answer Eng. Islam Al-Jarrah

5.  Pulley A is twice pulley B, Pulley B is the Driver.  What is the speed, direction, force and number of turns? Answer Eng. Islam Al-Jarrah

6.  Pulley "A" is half the size of pulley "B" and rotates a full circle twice.  What is the minimum weight that can hang from pulley "A" to just balance the 10kg mass hanging from pulley "B"?  How many times will pulley "A" make a full rotation? Answer Eng. Islam Al-Jarrah

7.  Pulley "A" is connected to the shaft of a motor. The motor can generate enough force to just lift a 8kg mass off the ground. Pulley "A" rotates in the direction of the arrow.  Is the system of pulleys on the right sufficient to provide enough force to lift the 30kg mass off the ground?  Will the 30kg mass be lifted off the ground by the motor? Explain. Answer Eng. Islam Al-Jarrah

8.  What is the force needed by the man to lift the 200 kg block? Answer Eng. Islam Al-Jarrah

9.  What is the output in revolutions per minute at Gear C?  Hint: (Speed gear A * Number of teeth Gear A) = (Speed gear B * Number of teeth gear B) Answer Eng. Islam Al-Jarrah

10.  What is the speed for Gear C, what is the direction?  What do we call Gear B? Answer Eng. Islam Al-Jarrah

11.  Calculate the output speed (the speed at which the blue gear moves) if: V1= 3000 (Orange gear) and t1=20 teeth, T2 = 50 teeth and T3 = 200 teeth Answer Eng. Islam Al-Jarrah

12.  In a compound gear, all gears are fixed on the same axel moving at the same speed.  This is an example of a “compound gear train”. Gear A rotates in a clockwise direction at 30 revs/min. What is the output in revs/min at D and what is the direction of rotation ?  TA=50, TB=20, TC=30, TD=10 Answer Eng. Islam Al-Jarrah

13.  What is the Gear Ratio if A is the Driver?  What is the Gear Ratio if C is the driver?  Which will have higher speed/force at the driven gear? Answer Eng. Islam Al-Jarrah

14.  Which Gears are the Idler Gears?  What is the purpose of the Idler Gear? Answer Eng. Islam Al-Jarrah

15. Answer Eng. Islam Al-Jarrah

16. Answer Eng. Islam Al-Jarrah

17. Answer Eng. Islam Al-Jarrah

18. Answer Eng. Islam Al-Jarrah

19. Answer Eng. Islam Al-Jarrah

20. Answer Eng. Islam Al-Jarrah

21.  Increase in speed if A is the driver  Same direction of rotation  B will rotate two turns as A turns once. Eng. Islam Al-Jarrah Home

22.  Opposite direction  Different speed.  A will rotate once and B twice Eng. Islam Al-Jarrah Home

23.  Same direction of Rotation.  The speed of A is half the speed of B  The force used by A is double the force exerted by B.  A will rotate once when B rotates twice. Eng. Islam Al-Jarrah Home

24.  5 Kg.  A will turn one time Eng. Islam Al-Jarrah Home

25.  Yes it is sufficient  The force needed by the motor will be less than 8  30/4 < 8  Yes it will be lifted Eng. Islam Al-Jarrah Home

26.  The effort needed will equal 50 since 200 / 4= 50.  4 is the number of ropes excluding the one connected to the effort. Eng. Islam Al-Jarrah Home

27.  60*20=10*S  S=60*20/10=120  120REV/min Eng. Islam Al-Jarrah Home

28.  90*30=15*S  S=90*30/15=180  S=180Rev/Min  The Direction of C will be the same as in A.  B is called an Idler. Eng. Islam Al-Jarrah Home

29.  3000*20=200*S  S=3000*20/200  S=300 Eng. Islam Al-Jarrah Home

30.  Direction of rotation will be the same at D & A  The speed is :  C & D will have the same speed so,  30*50=20*SB  Sb=75  Sc=75  So, 75*30=10*Sd  Sd=225 Eng. Islam Al-Jarrah Home

31.  When A is the Driver ◦ GR=15/30=1/2  When C is the Driver: ◦ GR=30/15=2  The first case will provide higher speed at the driven gear, but the second case will provide more force. Eng. Islam Al-Jarrah Home

32.  All the gears between the driver and the driven are called idlers and are used to make the driven gear rotate at the same direction of the Driver gear. Eng. Islam Al-Jarrah Home

33. Eng. Islam Al-Jarrah Home

34. Eng. Islam Al-Jarrah Home

35. Eng. Islam Al-Jarrah Home

36. Eng. Islam Al-Jarrah Home

37. Eng. Islam Al-Jarrah Home

38. Eng. Islam Al-Jarrah Home