Concept explainers
Two hemispheres having an inner radius of 2 ft and wall thickness of 0.25 in. are fitted together, and the inside pressure is reduced to − 10 psi. If the coefficient of static friction is μs = 0.5 between the hemispheres, determine (a) the torque T needed to initiate the rotation of the top hemisphere relative to the bottom one, (b) the vertical force needed to pull the top hemisphere of the bottom one, and (c) the horizontal force needed to slide the top hemisphere off the bottom one.
Want to see the full answer?
Check out a sample textbook solutionChapter 8 Solutions
CODE/MINES MECHANICS MATERIALS >IC<
Additional Engineering Textbook Solutions
Mechanics of Materials, 7th Edition
Thermodynamics: An Engineering Approach
Vector Mechanics for Engineers: Statics, 11th Edition
Foundations of Materials Science and Engineering
Vector Mechanics for Engineers: Dynamics
Vector Mechanics for Engineers: Statics
- The block brake consists of a pin-connected lever and friction block at BB. The coefficient of static friction between the wheel and the lever is μsμs = 0.3, and a torque of 5 N⋅mN⋅m is applied to the wheel. Determine if the brake can hold the wheel stationary when the force applied to the lever is (a) PP = 30 NN, (b) PP = 70 NN. Draw the free-body diagram of the wheel. Draw the vectors starting at the black dots. The location and orientation of the vectors.arrow_forwardThe leather rein used to fasten the horse to the hitching rail weighs 3.5 oz per foot. The coefficient of static friction between the rail and the rein is 0.6. If a 34-lb force acting on the bridle is sufficient to restrain the horse, determine the smallest safe length L for the free end of the rein.arrow_forwardThe screw of the clamp has a square thread of pitch 0.16 in. and a mean diameter of 0.6 in. The coefficient of static friction between the threads is 0.4. Determine (a) the torque C0 that must be applied to the screw in order to produce a 28-lb clamping force at A; and (b) the torque required to loosen the clamp.arrow_forward
- The square-threaded screw 0f the C-clamp has a mean diameter of 8 mm and a pitch of 1.6 mm. The coefficient of static friction between the threads is 0.2. If the torque C=1.50Nm is used to tighten the clamp, determine (a) the clamping force; and (b) the torque required to loosen the clamp.arrow_forwardThe two homogeneous bars AB and BC are connected with a pin at B and placed between rough vertical walls. If the coefficient of static friction between each bar and the wall is 0.25, determine the largest angle 6 for which the assembly will remain at rest.arrow_forwardA square threaded screw is used to clamp two boards together. The clamping force on the boards is 1000 lb, determine the torque needed to tighten the score to this compressive force. The double square-threaded screw has a mean diameter of 1.0 in. and a pitch of 0.25 in. The coefficient of static friction is μs=0.15arrow_forward
- The required clamping force at the board A is to be 1.7 kN . The square-threaded screw has a mean radius of 10 mm and a lead of 3 mm, and the coefficient of static friction is 0.3. (Figure 1) Determine the torque M that must be applied to the screw to tighten it down. Express your answer to three significant figures and include the appropriate units.arrow_forwardUsing the coefficients of static friction indicated, determine the largest vertical force PP which can be applied to the cord without causing motion. Express your answer to three significant figures and include the appropriate units.arrow_forwardAn elevator type lift is being designed to raise a load up to 5,000pounds between floors. Twosquare-thread lead screws, 1.5 inches in (major) diameter, are used for this application. Determine the torque required to raise this lift if the moving part of the elevator weighs 800 pounds and the coefficient of friction is assumed to be 0.15.arrow_forward
- A 60-kg cabinet is mounted on casters that can be locked to prevent their rotation. The coefficient of static friction between the floor and each caster is 0.35. 3. If h = 600 mm, determine the magnitude of the force P (in N) required to move the cabinet to the right if the casters at A are locked and the casters at B are free to rotate. (ANSWER: 72.5)arrow_forwardThe block brake is used to prevent the wheel from rotating when it is subjected to a torque moment M0. If the coefficient of static friction between the wheel and the block is us, determine the minimum force P that must be applied.arrow_forwardCouple forces of F= 35 N are applied to the handle of the machinist's vise. The guide at B is smooth. The single square-threaded screw has a mean radius of 6 mm and a lead of 8 mm , and the coefficient of static friction is μs= 0.27.arrow_forward
- International Edition---engineering Mechanics: St...Mechanical EngineeringISBN:9781305501607Author:Andrew Pytel And Jaan KiusalaasPublisher:CENGAGE L