ME3112 Week 7 Tutorial 1

ME 3112 Mechanics of Machines Tutorial 1 Does the Bird’s Launch Speed Depend on the Angle?

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Question 1 (Beer and Johnston, 3rd SI Ed) The motion of the slender 250 mm rod AB is guided by pins at A and B that slide freely in slots cut in a vertical plate as shown. Knowing that the rod is released from reset when q is 0 degree, determine the velocity of the pin at B when q is 90 degrees. Answer : 1.262 m/s upward ME3112

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Question 2 (17.35 Beer and Johnston) The 9 kg cradle is supported as shown by two uniform disks that roll without sliding at all surfaces of contact. The mass of each disk is m = 6 kg and the radius of each disk is r = 80 mm. Knowing that the system is initially at rest, determine the velocity of the cradle after it has moved 250 mm. (Answer 1054 m/s pointing right)

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Question 3 A uniform rod is hinged at two ends A and B by a slinder and a disk. The disk at A has a mass of 10 kg and a radius of 0.1 m. The mass and the length of the rod are 5 kg and 0.6 m respectively. The mass of the slider at B can be assumed to be negligible. The disk at A rolls on the horizontal surface without slipping. The friction of the slider at B can be neglected. The assembly is released at rest when q is equal to 60 degrees. Determine the angular velocity of the rod when the rod is in the horizontal configuration with q equal to zero degree. (answer: wR = 6.52 rad/s) ME3112

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Question 4 A uniform rod is hinged at two ends A and B by two blocks of negligible mass sliding freely along two slots. The length and mass of the rod are 0.8 m and 10 kg respectively. The rod is initially at rest when q is equal to zero degree. A force P of 50 N is applied at B. Determine the angular velocity of the rod when the angle q is 45 degrees. (answer: w2 = 6.11 rad/s)

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