Date: February-12-16 Time: 2:00:28 PM TEST REPORT Question file: P12-2006 Copyright: Test Date: 21/10/2010 Test Name: EquilibriumPractice Test Form: 0 Test Version: 0 Test Points: 138.00 Test File: EquilibriumPractice Test Path: H:\LXRData\Ph12\EquilibriumPractice.LXRTest
1. A 6.0 m uniform beam of mass 25 kg is suspended by a cable as shown. An 85 kg object hangs from one end. What is the tension in the cable? (7.00 marks) 2. (7.00 marks) The above diagram shows a uniform beam hinged at point P. The force of gravity on the beam is 425 N. Find the magnitude and direction of the reaction force at the hinge. 3. A uniform 0.122 kg rod of 0.90 m length is used to suspend two masses as shown below. At what distance x should the 0.20 kg mass be placed to achieve static equilibrium? A. 0.30 m B. 0.50 m C. 0.63 m D. 0.75 m 4. Calculate the force acting in the bar 'BC' if its mass is considered negligible.
5. A uniform 12 kg beam of length 3.00 m holding a 45 kg mass is attached by a wire to a wall as shown. (7.00 marks) What is the tension in the wire? 6. A 25 kg droid rests on a 5.0 m long shelf supported by two cables as shown. The mass of the shelf is 12 kg. Find the tension in each cable. (7.00 marks) 7. A uniform ladder is resting against a wall and makes an angle of 53 to the ground. If the force that the wall exerts on the ladder has components A x = 30.0 N and A y = 20.0 N, find the weight of the ladder and the x, y components of the force the ground exerts on the ladder at B. 8. If the mass of the boom is 8.5 kg, what is the force of tension in the cable? (3.00 marks)
9. In desert areas, such as Palm Springs California, regular high winds can be a dependable source of power. Wind turbines, such as the one shown below, are held in place by support cables, and generate electricity that is sent to a collecting station. 10. What is the force in the support cable to just hold the 250.0 kg wind generator shown above? Consider the mass of the supporting pole to be negligible, and assume that the cable is connected to the center of mass of the turbine. The bank at point 'A' can support only 600 N. How far would our 60 kg, friend get from 'B' on the 20 kg, 6.0 m beam before the bank at 'A' gives away? 11. A uniform 2.00 m long bar has a mass of 4.0 kg. A 5.0 kg mass is attached at one end and a 7.0 kg mass is attached at the opposite end. Calculate the magnitude and location of another force, F, required to produce static equilibrium. (6.00 marks) 12. (5.00 marks) Calculate the tension in supporting cable if the 12.0 kg ball is hanging from the middle of the uniform 5.00 kg beam.
13. Two cables are used to support a 24 kg mass on a 1.6 m long 8.0 kg uniform horizontal beam as shown. What is the tension T in the right cable? A. 130 N B. 150 N C. 190 N D. 300 N 14. A 5.0 kg, 6.0 m ladder is placed against a smooth wall so that it makes an angle of 80 to the horizontal. A 70 kg person stands 4.0 m from the bottom of the ladder. Solve for the smallest force of friction between the ladder and the ground necessary to keep the ladder from sliding. (5.00 marks) 15. One type of hand-held scale uses a 0.50 kg steel beam to support a large object and a smaller mass in static equilibrium as shown. (cg = center of gravity of beam) What is the mass of the large object? A. 0.35 kg B. 0.42 kg C. 0.63 kg D. 1.36 kg 16. If the mass of the boom is 9.2 kg, what is the force of tension in the cable? 17. The diagram below shows a uniform boom of length 2.6 m and mass 53 kg. The boom is hinges to the wall at point A and supported by a cable as shown. What is the vertical component of the force acting on the boom at point A?
18. A 65 kg man is 3.0 m up a 5.0 m, 16 kg ladder leaning against a smooth wall at an angle of 72 as shown below. What minimum force of friction between the ladder and the floor is required to keep the ladder from sliding? (5.00) 19. For the situation shown : a) Find the force (F) needed to produce translational equilibrium. b) Find the position (x) needed to produce rotational equilibrium. (6.00 marks) 20. A 4.2 m long uniform post is supported by a cable having a tension of 1 700 N. What is the mass of this post? A. 160 kg B. 260 kg C. 300 kg D. 530 kg 21. Two forces act on a uniform beam suspended by a cord at its center as shown below. If the beam is in rotational equilibrium, what is the distance X? A. 0.27 m B. 0.60 m C. 1.7 m D. 3.8 m 22. Which of the following are correct units for torque? N/m N/kg N s N m A. B. C. D.
23. A 3.5 m beam of mass 54 kg is supported by a cord attached at the 3.0 m position and at an angle as shown in the diagram. The tension in the cord is 730 N. What is the magnitude of the torque produced by the cord about the hinge? A. 310 Nm B. 930 Nm C. 2000 Nm D. 2200 Nm 24. Calculate the torque caused by the 7.5 kg mass. A. 7.5 Nm B. 74 Nm C. 1.5 x 10 2 Nm D. 2.6 x 10 2 Nm 25. Which of the following demonstrates the application of torque? A. Pulling a block across a floor B. Pushing a block up an incline C. Using a screwdriver to turn a screw D. Stopping a block from sliding down an inclne 26. What is the torque acting on the 4.3 m bar 'AB' shown below because of the 65 N force? A. 140 Nm B. 242 Nm C. 280 Nm D. 161 Nm 27. A student uses a wrench to loosen a very tight nut in the position shown. In which of the following would the student have more success at loosening the nut? A. B. C. D.
28. The diagram shows a metre stick with forces being exerted on it. This metre stick is in: A. tranlational equilibrium and rotational equilibrium B. translational equilibrium but not rotational equilibrium C. rotational equilibrium but not translational equilibrium D. neither translational nor rotational equilibrium 29. A very light bamboo fishing rod 3.0 m long is pivoted at one end. It is held in equilibrium by a horizontal force while a fish pulls on a fishline attached to the rod as shown below. How much force F does the fishline exert on the rod? A. 5.4 N B. 6.2 N C. 9.4 N D. 11 N 30. A 1.6 kg ball is held in the hand of a fully extended 11.2 kg arm as shown. (cg = centre of gravity) What is the total torque about the shoulder joint due to the ball and to this arm? A. 17 Nm B. 19 Nm C. 35 Nm D. 38 Nm 31. In which direction should a force act on the boom so that it creates a minimum torque about the hinge? A. W B. X C. Y D. Z
32. A student uses a wrench to apply a constant force to turn a nut. He applies the force at various angles and measures the amount of torque produced at each of the angles. The torque data collected by the student along with the sine of the angles is shown below: Torque (N m) 4.0 11 17 22 25 sinθ 0.14 0.42 0.66 0.86 0.98 a) Plot a graph of torque versus sinθ on the graph provided. (2 marks) b) Calculate the slope of your line including units. (1 mark) c) Use the slope of your graph to determine the amount of constant force the student used throughout his experiment. (2 marks) 33. Determine the sum of the torques about the point P for the two forces shown below acting on a very light wooden beam. (Ignore its weight.) A. 10 N m B. 17 N m C. 35 N m D. 85 N m 34. A crane is used to lift one end of a uniform 15 m long pipe with a mass of 730 kg as shown in the diagram below. What is the minimum force of tension in the crane cable to just lift the end of the pipe off the ground? A. 3.7 x 10 2 N B. 4.8 x 10 2 N C. 3.6 x 10 3 N D. 7.2 x 10 3 N 35. The diagram below shows a force F applied in several different directions at the point P on a hinged beam. In which direction will the force produce the smallest torque about the hinge? A. 1 B. 2 C. 3 D. 4 36. The unit for torque is... A. J B. Nm C. Ns D. kgm/s
37. The diagram at right shows a beam of uniform cross-section resting on the ground. Its mass is 334 kg and its length is 11.6 m. What must be the force of tension in the cable to just lift the end of the beam off the ground? A. 1.67 x 10 2 N B. 1.64 x 10 3 N C. 3.27 x 10 3 N D. 8.18 x 10 3 N 38. In which of the following situations does force F produce a counter-clockwise torque about point P? A. B. C. D. Use the following information to answer the next 1 question(s). A 2.0 kg meter stick has a 5.0 kg mass suspended from the 75 cm mark. Support 'A' is at the zero mark and support 'B' is at the 100 cm mark. 39. Calculate the force at 'A'. 0.0 N 22 N 47 N 69 N A. B. C. D. 40. (0.00 marks) Given the 2.0 m, 5.0 kg bar shown above, calculate the force at point 'A'. 41. What are the tensions T 1 and T 2 in the two ropes holding the 36 kg mass as shown? A. B. C. D. Tension T 1 Tension T 2 180 N 180 N 180 N 270 N 350 N 180 N 350 N 350 N
42. A picture on which the force of gravity is 190 N is supported by a wire, as shown in the diagram. What is the magnitude of the force of tension in the wire? A. 119 N B. 158 N C. 238 N D. 316 N 43. A picture on which the force of gravity is 170 N is supported by a wire, as shown in the diagram. What is the magnitude of the force of tension in the wire? A. 85 N B. 92 N C. 1.7 x 10 2 N D. 2.3 x 10 2 N 44. The diagram below shows a water tank suspended by two strings. If the force of gravity on the tank is 290 N, what is the tension in each wire? A. 1.7 x 10 2 N B. 2.1 x 10 2 N C. 2.5 x 10 2 N D. 3.6 x 10 2 N 45. A 110 kg object is supported by two ropes attached to the ceiling. What is the tension T in the right-hand rope? A. 460 N B. 540 N C. 930 N D. 1 300 N 46. Solve for the tension in the wire labeled T 1.
47. A bird sits on a telephone wire midway between two poles that are 20 m apart. The wire, assumed to be weightless, sags by 0.5 m. If the tension in the wire is 90 N, what is the mass of the bird? 48. What is the magnitude of the sum of the two forces shown in the diagram below? A. 46 N B. 102 N C. 137 N D. 142 N 49. Two cables suspend a 210 kg object as shown. What is the tension in the right cable? A. 1200 N B. 1900 N C. 2100 N D. 3900 N 50. A 27 kg mass is suspended by two ropes as shown above. Find the force of tension F 1 and F 2. 51. The diagram below shows a 55.0 kg pendulum bob in equilibrium, held as shown by a horizontal rope. What is the force of tension in the horizontal rope? A. 39 N B. 309 N C. 377 N D. 442 N 52. If the only forces acting on the object shown below are equal in magnitude, which of the following is not possible? A. B. C. D. The object is at rest. The object is accelerating to the left. The object is moving with constant velocity to the right. The object is moving with constant velocity towards the top of the page.
Use the following information to answer the next 1 question(s). A 250 kg load is supported by two cables as shown in the diagram below. 53. Calculate the tension in supporting cable #1. A. 2.5 x 10 2 N B. 2.5 x 10 3 N C. 3.3 x 10 3 N D. 3.7 x 10 3 N 54. An artist must push with a minimum force of 75 N at an angle of 45 from the horizontal to a picture to hold it in equilibrium. The coefficient of friction between the wall and the picture frame is 0.30. What is the mass of the picture? A. 1.6 kg B. 2.3 kg C. 3.8 kg D. 7.0 kg 55. A 5.0 kg mass is suspended by a rope. A horizontally directed force F is applied to the mass. What magnitude of force is needed to produce an angle of θ = 65º? A. 21 N B. 23 N C. 44 N D. 110 N 56. A 450 N chandelier is supported by three cables as shown in the diagram. What is the tension in the horizontal cable? A. 46 N B. 260 N C. 450 N D. 520 N 57. Which one of the following horizontal forces could be arranged to leave an object in equilibrium? A. 25, 50, and 100 N B. 5, 10, 20, and 50 N C. 4, 10, 16, and 32 N D. 6, 10, 14, and 30 N
58. A 5.0 kg mass suspended by a rope is pulled to the left by a horizontal force of 18 N. What is angle θ? A. 16º B. 20º C. 70º D. 74º 59. State the condition for translational equilibrium A. B. C. D. forces = 0 forces 0 torques = 0 torques 0 60. A physics exam booklet lying on a table in front of you is in translational equilibrium because A. there are no forces acting on it. B. the forces acting on it are balanced. C. the force due to gravity is holding it down. D. surface friction is preventing it from sliding.