Vector Mechanics for Engineers: Statics and Dynamics
12th Edition
ISBN: 9781259977251
Author: BEER
Publisher: MCG
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Textbook Question
Chapter 16.2, Problem 16.80P
An athlete performs a leg extension on a machine using a 20-kg mass at A located 400 mm away from the knee joint at center O. Biomechanical studies show that the patellar tendon inserts at B, which is 100 mm below point O and 20 mm from the center line of the tibia (see figure). The mass of the lower leg and foot is 5 kg, the center of gravity of this segment is 300 mm from the knee, and the radius of gyration about the knee is 350 mm. Knowing that the leg is moving at a constant angular velocity of 30 degrees per second when θ = 60°, determine (a) the force F in the patellar tendon, (b) the magnitude of the joint force at the knee joint center O.
Fig. P16.80
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Chapter 16 Solutions
Vector Mechanics for Engineers: Statics and Dynamics
Ch. 16.1 - Two pendulums, A and B, with the masses and...Ch. 16.1 - Two pendulums, A and B, with the masses and...Ch. 16.1 - Two solid cylinders, A and B, have the same mass m...Ch. 16.1 - Prob. 16.1FBPCh. 16.1 - Prob. 16.2FBPCh. 16.1 - Prob. 16.3FBPCh. 16.1 - The 400-lb crate shown is lowered by means of two...Ch. 16.1 - A 60-lb uniform thin panel is placed in a truck...Ch. 16.1 - A 60-lb uniform thin panel is placed in a truck...Ch. 16.1 - A loading car is at rest on a track forming an...
Ch. 16.1 - A 2100-lb rear-wheel-drive tractor carries a 900...Ch. 16.1 - A uniform rod BC of mass 4 kg is connected to a...Ch. 16.1 - A 2000-kg truck is being used to lift a 400-kg...Ch. 16.1 - The support bracket shown is used to transport a...Ch. 16.1 - Prob. 16.8PCh. 16.1 - A 20-kg cabinet is mounted on casters that allow...Ch. 16.1 - Solve Prob. 16.9, assuming that the casters are...Ch. 16.1 - Prob. 16.11PCh. 16.1 - Prob. 16.12PCh. 16.1 - The retractable shelf shown is supported by two...Ch. 16.1 - Bars AB and BE, each with a mass of 4 kg, are...Ch. 16.1 - At the instant shown, the tensions in the vertical...Ch. 16.1 - Three bars, each of mass 3 kg, are welded together...Ch. 16.1 - Members ACE and DCB are each 600 mm long and are...Ch. 16.1 - A prototype rotating bicycle rack is designed to...Ch. 16.1 - The control rod AC is guided by two pins that...Ch. 16.1 - The coefficients of friction between the 30-lb...Ch. 16.1 - Prob. 16.21PCh. 16.1 - Prob. 16.22PCh. 16.1 - For a rigid body in translation, show that the...Ch. 16.1 - For a rigid body in centroidal rotation, show that...Ch. 16.1 - It takes 10 min for a 2.4-Mg flywheel to coast to...Ch. 16.1 - The rotor of an electric motor has an angular...Ch. 16.1 - The 10-in.-radius brake drum is attached to a...Ch. 16.1 - The 10-in.-radius brake drum is attached to a...Ch. 16.1 - The 100-mm-radius brake drum is attached to a...Ch. 16.1 - The 180-mm-radius disk is at rest when it is...Ch. 16.1 - Solve Prob. 16.30, assuming that the direction of...Ch. 16.1 - In order to determine the mass moment of inertia...Ch. 16.1 - The flywheel shown has a radius of 20 in., a...Ch. 16.1 - Each of the double pulleys shown has a mass moment...Ch. 16.1 - Two disks A and B, of mass mA = 2 kg and mB = 4...Ch. 16.1 - Two disks A and B, of mass mA = 2 kg and mB = 4...Ch. 16.1 - Gear A weighs 1 lb and has a radius of gyration of...Ch. 16.1 - The 25-lb double pulley shown is at rest and in...Ch. 16.1 - A belt of negligible mass passes between cylinders...Ch. 16.1 - Prob. 16.40PCh. 16.1 - Disk A has a mass of 6 kg and an initial angular...Ch. 16.1 - Prob. 16.42PCh. 16.1 - Disk A has a mass mA = 4 kg, a radius rA = 300 mm,...Ch. 16.1 - Disk B is at rest when it is brought into contact...Ch. 16.1 - Prob. 16.45PCh. 16.1 - Prob. 16.46PCh. 16.1 - For a rigid body in plane motion, show that the...Ch. 16.1 - A uniform slender rod AB rests on a frictionless...Ch. 16.1 - Prob. 16.49PCh. 16.1 - Prob. 16.50PCh. 16.1 - Prob. 16.51PCh. 16.1 - A 250-lb satellite has a radius of gyration of 24...Ch. 16.1 - A rectangular plate of mass 5 kg is suspended from...Ch. 16.1 - Prob. 16.54PCh. 16.1 - A drum with a 200-mm radius is attached to a disk...Ch. 16.1 - A drum with a 200-mm radius is attached to a disk...Ch. 16.1 - The 12-lb uniform disk shown has a radius of r =...Ch. 16.1 - Prob. 16.58PCh. 16.1 - Prob. 16.59PCh. 16.1 - 16.60 and 16.61The 400-lb crate shown is lowered...Ch. 16.1 - Prob. 16.61PCh. 16.1 - Two uniform cylinders, each of weight W = 14 lb...Ch. 16.1 - Prob. 16.63PCh. 16.1 - Prob. 16.64PCh. 16.1 - A uniform slender bar AB with a mass m is...Ch. 16.1 - Prob. 16.66PCh. 16.1 - 16.66 through 16.68A thin plate of the shape...Ch. 16.1 - 16.66 through 16.68A thin plate of the shape...Ch. 16.1 - A sphere of radius r and mass m is projected along...Ch. 16.1 - Solve Prob. 16.69, assuming that the sphere is...Ch. 16.1 - A bowler projects an 8-in.-diameter ball weighing...Ch. 16.1 - Prob. 16.72PCh. 16.1 - A uniform sphere of radius r and mass m is placed...Ch. 16.1 - A sphere of radius r and mass m has a linear...Ch. 16.2 - A cord is attached to a spool when a force P is...Ch. 16.2 - Prob. 16.5CQCh. 16.2 - Prob. 16.6CQCh. 16.2 - Prob. 16.7CQCh. 16.2 - Prob. 16.5FBPCh. 16.2 - Two identical 4-lb slender rods AB and BC are...Ch. 16.2 - Prob. 16.7FBPCh. 16.2 - Prob. 16.8FBPCh. 16.2 - Show that the couple I of Fig. 16.15 can be...Ch. 16.2 - A uniform slender rod of length L = 900 mm and...Ch. 16.2 - A crate of mass 80 kg is held in the position...Ch. 16.2 - A uniform slender rod of length L = 36 in. and...Ch. 16.2 - In Prob. 16.78, determine (a) the distance h for...Ch. 16.2 - An athlete performs a leg extension on a machine...Ch. 16.2 - Prob. 16.81PCh. 16.2 - A turbine disk weighing 50 lb rotates at a...Ch. 16.2 - The 80-lb tailgate of a car is supported by the...Ch. 16.2 - A uniform rod of length L and mass m is supported...Ch. 16.2 - Three stage lights are mounted on a pipe fixture...Ch. 16.2 - An adapted launcher uses a torsional spring about...Ch. 16.2 - A 4-kg slender rod is welded to the edge of a 3-kg...Ch. 16.2 - Prob. 16.88PCh. 16.2 - The object ABC consists of two slender rods welded...Ch. 16.2 - A 3.5-kg slender rod AB and a 2-kg slender rod BC...Ch. 16.2 - A 9-kg uniform disk is attached to the 5-kg...Ch. 16.2 - Derive the equation MC=IC for the rolling disk of...Ch. 16.2 - Prob. 16.93PCh. 16.2 - Prob. 16.94PCh. 16.2 - Prob. 16.95PCh. 16.2 - Prob. 16.96PCh. 16.2 - A 40-kg flywheel of radius R = 0.5 m is rigidly...Ch. 16.2 - Prob. 16.98PCh. 16.2 - 16.98 through 16.101A drum of 80-mm radius is...Ch. 16.2 - 16.98 through 16.101A drum of 80-mm radius is...Ch. 16.2 - 16.98 through 16.101A drum of 80-mm radius is...Ch. 16.2 - 16.102 through 16.105A drum of 4-in. radius is...Ch. 16.2 - 16.102 through 16.105A drum of 4-in. radius is...Ch. 16.2 - 16.102 through 16.105A drum of 4-in. radius is...Ch. 16.2 - 16.102 through 16.105A drum of 4-in. radius is...Ch. 16.2 - 16.106 and 16.107A 12-in.-radius cylinder of...Ch. 16.2 - 16.106 and 16.107A 12-in.-radius cylinder of...Ch. 16.2 - Gear C has a mass of 5 kg and a centroidal radius...Ch. 16.2 - Two uniform disks A and B, each with a mass of 2...Ch. 16.2 - A single-axis personal transport device starts...Ch. 16.2 - A hemisphere of weight W and radius r is released...Ch. 16.2 - A hemisphere of weight W and radius r is released...Ch. 16.2 - The center of gravity G of a 1.5-kg unbalanced...Ch. 16.2 - A small clamp of mass mB is attached at B to a...Ch. 16.2 - Prob. 16.115PCh. 16.2 - A 4-lb bar is attached to a 10-lb uniform cylinder...Ch. 16.2 - The uniform rod AB with a mass m and a length of...Ch. 16.2 - Prob. 16.118PCh. 16.2 - Prob. 16.119PCh. 16.2 - Prob. 16.120PCh. 16.2 - End A of the 6-kg uniform rod AB rests on the...Ch. 16.2 - End A of the 6-kg uniform rod AB rests on the...Ch. 16.2 - End A of the 8-kg uniform rod AB is attached to a...Ch. 16.2 - The 4-kg uniform rod ABD is attached to the crank...Ch. 16.2 - The 3-lb uniform rod BD is connected to crank AB...Ch. 16.2 - The 3-lb uniform rod BD is connected to crank AB...Ch. 16.2 - The test rig shown was developed to perform...Ch. 16.2 - Solve Prob. 16.127 for = 90. 16.127The test rig...Ch. 16.2 - The 4-kg uniform slender bar BD is attached to bar...Ch. 16.2 - The motion of the uniform slender rod of length L...Ch. 16.2 - At the instant shown, the 20-ft-long, uniform...Ch. 16.2 - A driver starts his car with the door on the...Ch. 16.2 - Prob. 16.133PCh. 16.2 - The hatchback of a car is positioned as shown to...Ch. 16.2 - The 6-kg rod BC connects a 10-kg disk centered at...Ch. 16.2 - Prob. 16.136PCh. 16.2 - In the engine system shown, l = 250 mm and b = 100...Ch. 16.2 - Solve Prob. 16.137 when = 90. 16.137In the engine...Ch. 16.2 - The 4-lb uniform slender rod AB, the 8-lb uniform...Ch. 16.2 - The 4-lb uniform slender rod AB, the 8-lb uniform...Ch. 16.2 - Two rotating rods in the vertical plane are...Ch. 16.2 - Two rotating rods in the vertical plane are...Ch. 16.2 - Two disks, each with a mass m and a radius r, are...Ch. 16.2 - A uniform slender bar AB of mass m is suspended as...Ch. 16.2 - A uniform rod AB, of mass 15 kg and length 1 m, is...Ch. 16.2 - The uniform slender 2-kg bar BD is attached to the...Ch. 16.2 - Prob. 16.147PCh. 16.2 - Prob. 16.148PCh. 16.2 - Prob. 16.149PCh. 16.2 - Prob. 16.150PCh. 16.2 - (a) Determine the magnitude and the location of...Ch. 16.2 - Prob. 16.152PCh. 16 - A cyclist is riding a bicycle at a speed of 20 mph...Ch. 16 - The forklift truck shown weighs 3200 lb and is...Ch. 16 - The total mass of the Baja car and driver,...Ch. 16 - Identical cylinders of mass m and radius r are...Ch. 16 - Prob. 16.157RPCh. 16 - The uniform rod AB of weight W is released from...Ch. 16 - Prob. 16.159RPCh. 16 - Prob. 16.160RPCh. 16 - A cylinder with a circular hole is rolling without...Ch. 16 - Two 3-kg uniform bars are connected to form the...Ch. 16 - A crate of mass 80 kg is held in the position...Ch. 16 - The Geneva mechanism shown is used to provide an...
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