VECTOR MECHANICS FOR ENGINEERS: STATICS
VECTOR MECHANICS FOR ENGINEERS: STATICS
12th Edition
ISBN: 9781260912814
Author: BEER
Publisher: MCG
bartleby

Videos

Textbook Question
Book Icon
Chapter 8.1, Problem 8.43P

Two 8-kg blocks A and B resting on shelves are connected by a rod of negligible mass. Knowing that the magnitude of a horizontal force P applied at C is slowly increased from zero, determine the value of P for which motion occurs and what that motion is when the coefficient of static friction between all surfaces is (a) μs = 0.40, (b) μs = 0.50.

Chapter 8.1, Problem 8.43P, Two 8-kg blocks A and B resting on shelves are connected by a rod of negligible mass. Knowing that

Fig. P8.43

(a)

Expert Solution
Check Mark
To determine

Find the magnitude of horizontal force P applied at C for which the motion occurs.

Answer to Problem 8.43P

The magnitude of the horizontal force P is 62.8N_.

The system slides_.

Explanation of Solution

Given information:

The mass of the blocks A and B is m=8kg.

The coefficient of static friction between the surfaces is μs=0.40.

Calculation:

Consider the blocks will slide to the right.

Find the weight (W) of the blocks A and B using the relation.

W=mg

Here, the acceleration due to gravity is g.

Consider the acceleration due to gravity is g=9.81m/s2.

Substitute 8 kg for m and 9.81m/s2 for g.

W=8×9.81=78.48N

Find the friction force at block A and B as follows.

FA=μsNAFB=μsNB

Here, the normal force at block A is NA and the normal force at block B is NB.

Show the free-body diagram of the shelves as in Figure 1.

VECTOR MECHANICS FOR ENGINEERS: STATICS, Chapter 8.1, Problem 8.43P

Resolve the vertical component of forces.

Fy=0NA+NB78.4878.48=0NA+NB=156.96N

Resolve the horizontal component of forces.

Fx=0PFAFB=0PμsNAμsNB=0P=μs(NA+NB)

Substitute 0.40 for μs and 156.96 N for (NA+NB).

P=0.40×156.96=62.8N

Therefore, the magnitude of the horizontal force P is 62.8N_.

Take moment about point B.

MB=0P(100)+NA(93.26)78.48(93.26)+FA(200)=0P(100)+NA(93.26)7,319.0448+μsNA(200)=0

Substitute 62.8 N for P and 0.40 for μs.

62.8(100)+NA(93.26)7,319.0448+0.40×NA(200)=06,280+93.26NA7,319.0448+80NA=0173.26NA=1,039.0448NA=6N>0

Therefore, the system slides_.

(b)

Expert Solution
Check Mark
To determine

Find the magnitude of horizontal force P applied at C for which the motion occurs.

Answer to Problem 8.43P

The systemrotatesaboutpointB_.

The magnitude of the horizontal force P is 73.2N_.

Explanation of Solution

Given information:

The mass of the blocks A and B is m=8kg.

The coefficient of static friction between the surfaces is μs=0.50.

Calculation:

Consider the blocks will slide to the right.

Find the weight (W) of the blocks A and B using the relation.

W=mg

Here, the acceleration due to gravity is g.

Consider the acceleration due to gravity is g=9.81m/s2.

Substitute 8 kg for m and 9.81m/s2 for g.

W=8×9.81=78.48N

Find the friction force at block A and B as follows.

FA=μsNAFB=μsNB

Here, the normal force at block A is NA and the normal force at block B is NB.

Resolve the vertical component of forces.

Fy=0NA+NB78.4878.48=0NA+NB=156.96NNB=156.96NA

Resolve the horizontal component of forces.

Fx=0PFAFB=0PμsNAμsNB=0P=μs(NA+NB)

Substitute 0.50 for μs and 156.96 N for (NA+NB).

P=0.50×156.96=78.48N

Therefore, the magnitude of the horizontal force P is 78.48N_.

Take moment about point B.

MB=0P(100)+NA(93.26)78.48(93.26)+FA(200)=0P(100)+NA(93.26)7,319.0448+μsNA(200)=0

Substitute 78.48 N for P and 0.50 for μs.

78.48(100)+NA(93.26)7,319.0448+0.50NA(200)=07,848+93.26NA7,319.0448+100NA=0193.26NA=528.9552NA=2.73N<0

Therefore, the systemrotatesaboutpointB_.

The value of NA=0.

Take moment about point B.

MB=0P(100)+NA(93.26)78.48(93.26)+FA(200)=0P(100)+NA(93.26)7,319.0448+μsNA(200)=0

Substitute 0 for NA and 0.50 for μs.

P(100)+(0)(93.26)7,319.0448+0.50(0)(200)=0100P+07,316.0448+0=0P=73.2N

Therefore, the magnitude of the horizontal force P is 73.2N_.

Want to see more full solutions like this?

Subscribe now to access step-by-step solutions to millions of textbook problems written by subject matter experts!
Students have asked these similar questions
First monthly exam Gas dynamics Third stage Q1/Water at 15° C flow through a 300 mm diameter riveted steel pipe, E-3 mm with a head loss of 6 m in 300 m length. Determine the flow rate in pipe. Use moody chart. Q2/ Assume a car's exhaust system can be approximated as 14 ft long and 0.125 ft-diameter cast-iron pipe ( = 0.00085 ft) with the equivalent of (6) regular 90° flanged elbows (KL = 0.3) and a muffler. The muffler acts as a resistor with a loss coefficient of KL= 8.5. Determine the pressure at the beginning of the exhaust system (pl) if the flowrate is 0.10 cfs, and the exhaust has the same properties as air.(p = 1.74 × 10-3 slug/ft³, u= 4.7 x 10-7 lb.s/ft²) Use moody chart (1) MIDAS Kel=0.3 Q3/Liquid ammonia at -20°C is flowing through a 30 m long section of a 5 mm diameter copper tube(e = 1.5 × 10-6 m) at a rate of 0.15 kg/s. Determine the pressure drop and the head losses. .μ= 2.36 × 10-4 kg/m.s)p = 665.1 kg/m³
2/Y Y+1 2Cp Q1/ Show that Cda Az x P1 mactual Cdf Af R/T₁ 2pf(P1-P2-zxgxpf) Q2/ A simple jet carburetor has to supply 5 Kg of air per minute. The air is at a pressure of 1.013 bar and a temperature of 27 °C. Calculate the throat diameter of the choke for air flow velocity of 90 m/sec. Take velocity coefficient to be 0.8. Assume isentropic flow and the flow to be compressible. Quiz/ Determine the air-fuel ratio supplied at 5000 m altitude by a carburetor which is adjusted to give an air-fuel ratio of 14:1 at sea level where air temperature is 27 °C and pressure is 1.013 bar. The temperature of air decreases with altitude as given by the expression The air pressure decreases with altitude as per relation h = 19200 log10 (1.013), where P is in bar. State any assumptions made. t = ts P 0.0065h
36 2) Use the method of MEMBERS to determine the true magnitude and direction of the forces in members1 and 2 of the frame shown below in Fig 3.2. 300lbs/ft member-1 member-2 30° Fig 3.2. https://brightspace.cuny.edu/d21/le/content/433117/viewContent/29873977/View

Chapter 8 Solutions

VECTOR MECHANICS FOR ENGINEERS: STATICS

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...
Knowledge Booster
Background pattern image
Mechanical Engineering
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, mechanical-engineering and related others by exploring similar questions and additional content below.
Similar questions
SEE MORE QUESTIONS
Recommended textbooks for you
Text book image
Elements Of Electromagnetics
Mechanical Engineering
ISBN:9780190698614
Author:Sadiku, Matthew N. O.
Publisher:Oxford University Press
Text book image
Mechanics of Materials (10th Edition)
Mechanical Engineering
ISBN:9780134319650
Author:Russell C. Hibbeler
Publisher:PEARSON
Text book image
Thermodynamics: An Engineering Approach
Mechanical Engineering
ISBN:9781259822674
Author:Yunus A. Cengel Dr., Michael A. Boles
Publisher:McGraw-Hill Education
Text book image
Control Systems Engineering
Mechanical Engineering
ISBN:9781118170519
Author:Norman S. Nise
Publisher:WILEY
Text book image
Mechanics of Materials (MindTap Course List)
Mechanical Engineering
ISBN:9781337093347
Author:Barry J. Goodno, James M. Gere
Publisher:Cengage Learning
Text book image
Engineering Mechanics: Statics
Mechanical Engineering
ISBN:9781118807330
Author:James L. Meriam, L. G. Kraige, J. N. Bolton
Publisher:WILEY
Differences between Temporary Joining and Permanent Joining.; Author: Academic Gain Tutorials;https://www.youtube.com/watch?v=PTr8QZhgXyg;License: Standard Youtube License