Vector Mechanics for Engineers: Statics
12th Edition
ISBN: 9781260501735
Author: BEER
Publisher: MCG
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Textbook Question
Chapter 8.3, Problem 8.91P
A loaded railroad car has a mass of 30 Mg and is supported by eight 800-mm-diameter wheels with 125-mm-diameter axles. Knowing that the coefficients of friction are μS = 0.020 and μk = 0.015, determine the horizontal force required (a) to start the car moving, (b) to keep the car moving at a constant speed. Neglect rolling resistance between the wheels and the rails.
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Please solve the question in handwriting step by step.
The coefficient of static friction µs between the 111-lb body and the 18° wedge is 0.17. Determine the magnitude of the force P required to begin raising
the 111-lb body if (a) rollers of negligible friction are present under the wedge, as illustrated, and (b) the rollers are removed and the coefficient of static
friction μs = 0.17 applies at this surface as well.
Answers:
(a) P =
(b) P =
M.
18°
111 lb
lb
lb
Three packages each of weight m = 9 kg A, B, and C are placed on a conveyor belt that is at rest. Between the belt and both
packages A and C, the coefficients of friction are Ms = 0.30 and Mk = 0.20; between package B and the belt, the coefficients
are Ms = 0.10 and Mk = 0.08. The packages are placed on the belt so that they are in contact with each other and at rest.
Determine which, if any, of the packages will move and the friction force acting on each package.
The frictional force acting on A is N
The frictional force acting on B is
N
The frictional force acting on C is
N
Note: please show correct step by step working out. And double check final answers. Also for frictional force A, B & C show their directions as well. Thanks!
Chapter 8 Solutions
Vector Mechanics for Engineers: Statics
Ch. 8.1 - Knowing that the coefficient of friction between...Ch. 8.1 - Two blocks A and B are connected by a cable as...Ch. 8.1 - A cord is attached to and partially wound around a...Ch. 8.1 - A 40-kg packing crate must be moved to the left...Ch. 8.1 - Determine whether the block shown is in...Ch. 8.1 - Prob. 8.2PCh. 8.1 - Prob. 8.3PCh. 8.1 - Prob. 8.4PCh. 8.1 - Prob. 8.5PCh. 8.1 - The 20-lb block A hangs from a cable as shown....
Ch. 8.1 - The 10-kg block is attached to link AB and rests...Ch. 8.1 - Considering only values of less than 90,...Ch. 8.1 - The coefficients of friction between the block and...Ch. 8.1 - The coefficients of friction between the block and...Ch. 8.1 - The 50-lb block A and the 25-lb block B are...Ch. 8.1 - The 50-lb block A and the 25-lb block B are...Ch. 8.1 - Three 4-kg packages A, B, and C are placed on a...Ch. 8.1 - Solve Prob. 8.13 assuming that package B is placed...Ch. 8.1 - A uniform crate with a mass of 30 kg must be moved...Ch. 8.1 - A worker slowly moves a 50-kg crate to the left...Ch. 8.1 - Prob. 8.17PCh. 8.1 - A 200-lb sliding door is mounted on a horizontal...Ch. 8.1 - Prob. 8.19PCh. 8.1 - Solve Prob. 8.19 assuming that the coefficients of...Ch. 8.1 - Prob. 8.21PCh. 8.1 - The cylinder shown has a weight W and radius r,...Ch. 8.1 - The 10-lb uniform rod AB is held in the position...Ch. 8.1 - In Prob. 8.23, determine the largest value of P...Ch. 8.1 - A 6. 5-m ladder AB leans against a wall as shown....Ch. 8.1 - A 6. 5-m ladder AB leans against a wall as shown....Ch. 8.1 - The press shown is used to emboss a small seal at...Ch. 8.1 - The machine base shown has a mass of 75 kg and is...Ch. 8.1 - The 50-lb plate ABCD is attached at A and D to...Ch. 8.1 - In Prob. 8.29, determine the range of values of...Ch. 8.1 - A window sash weighing 10 lb is normally supported...Ch. 8.1 - A 500-N concrete block is to be lifted by the pair...Ch. 8.1 - Prob. 8.33PCh. 8.1 - A driver starts the engine of an automobile that...Ch. 8.1 - Prob. 8.35PCh. 8.1 - Prob. 8.36PCh. 8.1 - A 1.2-m plank with a mass of 3 kg rests on two...Ch. 8.1 - Two identical uniform boards, each with a weight...Ch. 8.1 - Prob. 8.39PCh. 8.1 - Prob. 8.40PCh. 8.1 - A 10-ft beam, weighing 1200 lb, is to be moved to...Ch. 8.1 - (a) Show that the beam of Prob. 8.41 cannot be...Ch. 8.1 - Two 8-kg blocks A and B resting on shelves are...Ch. 8.1 - A slender steel rod with a length of 225 mm is...Ch. 8.1 - In Prob. 8.44, determine the smallest value of ...Ch. 8.1 - Two slender rods of negligible weight are...Ch. 8.1 - Two slender rods of negligible weight are...Ch. 8.2 - The machine part ABC is supported by a...Ch. 8.2 - Solve Prob. 8.48 assuming that the wedge is moved...Ch. 8.2 - 8.50 and 8.51 Two 6 wedges of negligible weight...Ch. 8.2 - 8.50 and 8.51 Two 6 wedges of negligible weight...Ch. 8.2 - The elevation of the end of the steel beam...Ch. 8.2 - Prob. 8.53PCh. 8.2 - Block A supports a pipe column and rests as shown...Ch. 8.2 - Block A supports a pipe column and rests as shown...Ch. 8.2 - Block A supports a pipe column and rests as shown...Ch. 8.2 - A 200-lb block rests as shown on a wedge of...Ch. 8.2 - A 15 wedge is forced into a saw cut to prevent...Ch. 8.2 - A 12 wedge is used to spread a split ring. The...Ch. 8.2 - The spring of the door latch has a constant of 1.8...Ch. 8.2 - Prob. 8.61PCh. 8.2 - Prob. 8.62PCh. 8.2 - Prob. 8.63PCh. 8.2 - A 15 wedge is forced under a 50-kg pipe as shown....Ch. 8.2 - A 15 wedge is forced under a 50-kg pipe as shown....Ch. 8.2 - Prob. 8.66PCh. 8.2 - Prob. 8.67PCh. 8.2 - Derive the following formulas relating the load W...Ch. 8.2 - The square-threaded worm gear shown has a mean...Ch. 8.2 - Prob. 8.70PCh. 8.2 - High-strength bolts are used in the construction...Ch. 8.2 - The position of the automobile jack shown is...Ch. 8.2 - For the jack of Prob. 8.72, determine the...Ch. 8.2 - Prob. 8.74PCh. 8.2 - Prob. 8.75PCh. 8.2 - Prob. 8.76PCh. 8.3 - A lever of negligible weight is loosely fitted...Ch. 8.3 - A 6-in.-radius pulley of weight 5 lb is attached...Ch. 8.3 - 8.79 and 8.80 The double pulley shown is attached...Ch. 8.3 - Prob. 8.80PCh. 8.3 - 8.81 and 8.82 The double pulley shown is attached...Ch. 8.3 - 8.81 and 8.82 The double pulley shown is attached...Ch. 8.3 - The block and tackle shown are used to raise a...Ch. 8.3 - The block and tackle shown are used to lower a...Ch. 8.3 - A scooter is to be designed to roll down a 2...Ch. 8.3 - The link arrangement shown is frequently used in...Ch. 8.3 - 8.87 and 8.88 A lever AB of negligible weight is...Ch. 8.3 - 8.87 and 8.88 A lever AB of negligible weight is...Ch. 8.3 - 8.89 and 8.90 A lever AB of negligible weight is...Ch. 8.3 - 8.89 and 8.90 A lever AB of negligible weight is...Ch. 8.3 - A loaded railroad car has a mass of 30 Mg and is...Ch. 8.3 - Prob. 8.92PCh. 8.3 - A 50-lb electric floor polisher is operated on a...Ch. 8.3 - The frictional resistance of a thrust bearing...Ch. 8.3 - Assuming that bearings wear out as indicated in...Ch. 8.3 - Assuming that the pressure between the surfaces of...Ch. 8.3 - Solve Prob. 8.93 assuming that the normal force...Ch. 8.3 - Determine the horizontal force required to move a...Ch. 8.3 - Knowing that a 6-in.-diameter disk rolls at a...Ch. 8.3 - A 900-kg machine base is rolled along a concrete...Ch. 8.3 - Solve Prob. 8.85 including the effect of a...Ch. 8.3 - Solve Prob. 8.91 including the effect of a...Ch. 8.4 - A rope having a weight per unit length of 0.4...Ch. 8.4 - A hawser is wrapped two full turns around a...Ch. 8.4 - Two cylinders are connected by a rope that passes...Ch. 8.4 - Two cylinders are connected by a rope that passes...Ch. 8.4 - The coefficient of static friction between block B...Ch. 8.4 - The coefficient of static friction S is the same...Ch. 8.4 - A band belt is used to control the speed of a...Ch. 8.4 - The setup shown is used to measure the output of a...Ch. 8.4 - The setup shown is used to measure the output of a...Ch. 8.4 - A flat belt is used to transmit a couple from drum...Ch. 8.4 - A flat belt is used to transmit a couple from...Ch. 8.4 - Prob. 8.114PCh. 8.4 - The speed of the brake drum shown is controlled by...Ch. 8.4 - Prob. 8.116PCh. 8.4 - The speed of the brake drum shown is controlled by...Ch. 8.4 - Bucket A and block C are connected by a cable that...Ch. 8.4 - Solve Prob. 8.118 assuming that drum B is frozen...Ch. 8.4 - Prob. 8.120PCh. 8.4 - 8.121 and 8.123 A cable is placed around three...Ch. 8.4 - Prob. 8.122PCh. 8.4 - 8.121 and 8.123 A cable is placed around three...Ch. 8.4 - A recording tape passes over the 20-mm-radius...Ch. 8.4 - Solve Prob. 8.124 assuming that the idler drum C...Ch. 8.4 - Prob. 8.126PCh. 8.4 - The axle of the pulley is frozen and cannot rotate...Ch. 8.4 - Prob. 8.128PCh. 8.4 - Prob. 8.129PCh. 8.4 - Prove that Eqs. (8.13) and (8.14) are valid for...Ch. 8.4 - Prob. 8.131PCh. 8.4 - Solve Prob. 8.112 assuming that the flat belt and...Ch. 8.4 - Solve Prob. 8.113 assuming that the flat belt and...Ch. 8 - 8.134 and 8.135 The coefficients of friction are S...Ch. 8 - 8.134 and 8.135 The coefficients of friction are S...Ch. 8 - A 120-lb cabinet is mounted on casters that can be...Ch. 8 - Prob. 8.137RPCh. 8 - The hydraulic cylinder shown exerts a force of 3...Ch. 8 - Prob. 8.139RPCh. 8 - Bar AB is attached to collars that can slide on...Ch. 8 - Two 10 wedges of negligible weight are used to...Ch. 8 - A 10 wedge is used to split a section of a log....Ch. 8 - In the gear-pulling assembly shown, the...Ch. 8 - A lever of negligible weight is loosely fitted...Ch. 8 - In the pivoted motor mount shown, the weight W of...
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