oad of 12 kN is raised by means of a screw jack. The mean diameter of the square threaded screw is 48 mm and the pitch is 12 mm. A force of 180 N is applied at the end of a lever to raise the load. Determine the length of the lever to be used and the mechanical advantage obtained. the screw self-locking? Take µ = 0.12

oad of 12 kN is raised by means of a screw jack. The mean diameter of the square threaded screw is 48 mm and the pitch is 12 mm. A force of 180 N is applied at the end of a lever to raise the load. Determine the length of the lever to be used and the mechanical advantage obtained. the screw self-locking? Take µ = 0.12

Mechanics of Materials (MindTap Course List)

9th Edition

ISBN:9781337093347

Author:Barry J. Goodno, James M. Gere

Publisher:Barry J. Goodno, James M. Gere

Chapter11: Columns

Section: Chapter Questions

Problem 11.2.1P: A rigid bar of length L is supported by a linear elastic rotational spring with rotational stiffness...

See similar textbooks

Similar questions

Two steel wines support a moveable overhead camera weighing W = 28 lb (see figure part a) used For close-up to viewing of field action at sporting, events. At some instant, wire I is at an angle a = 22° to the horizontal and wire 2 is at angle fi = 40°. Wires I and 2 have diameters of 30and 35 mils, respectively. (Wire diameters are often expressed in mils; one mil equals 0.001 in.) (a) Determine the tensile stresses s and s2 in the two wires. (b) If the stresses in wires 1 and 2 must be the same, what is the required diameter of wire 1 ? (c) To stabilize the camera for windy outdoor conditions, a third wire is added (see figure part b). Assume the three wires meet at a common point coordinates (0, 0. 0) above the camera at the instant shown in figure part b. Wire I is attached to a support at coordinates (75 ft, 48 ft, 70 Ft). Wire 2 is supported at (-70 ft. 55 ft, 80 Ft). Wire 3 is supported at (-10 ft. -85 Ft, 75 ft). Assume that all three wires have a diameter of 30 mils. Find the tensile stresses in all three wires
A cantilever aluminum column has a square tube cross section with an outer dimension of 150 mm. The column has a length L = 4 m and is designed to support an axial load of 45 kN. Find the minimum required thickness of the section if the factor of safety n = 2.5 with respect to buckling. Assume that the modulus of elasticity is 72 GPa and the proportional limit is 480 MPa.
A rigid bar of length L is supported by a linear elastic rotational spring with rotational stiffness ßRat A. Determine the critical load Pcr for the structure.
The rails of a railroad track are welded together at their ends (to form continuous rails and thus eliminate the clacking sound of the wheels) when the temperature is 60°F. What compressive stress ?? =6.5×10-6 /? is produced in the rails when they are heated by the sun to 120"F if the coefficient of thermal expansion a = the modulus of elasticity E = 30 × 106 psi?
A metal bar AB of a weight Ills suspended by a system of steel wires arranged as shown in the figure. The diameter of the wires is 5/64 in., and the yield stress of the steel is 65 ksi. Determine the maximum permissible weight W max for a factor of safety of 1.9 with respect to yielding.
A spring has a load of 50 lb with a spring index of 8. If the induced stress is 90ksi, determine the wire diameter.
The uniform 3830 kg bar is supported by a smooth wall at A and by a pin at B that is in double shear. Determine the diameter of the smallest pin that can be used if its working shear stress is 74 MPa. Note: Gravitational acceleration is equal to 9.81 m/s2 LAB=10 m; L1=6 m.
PROBLEM: 3 A helical spring made of C50 steel has an outside diameter of 91 mm and a wire diameter of 11 mm. The spring has to support a maximum axial load of 1.25 KN. Determine the maximum shear stress and total deflection. If the springs have 14 coils with ends ground flat. Determine also the factor of safety. Take G = 0.85x102 KN/mm2.Take yield strength of C50 as 380 N/mm2.
Construct the buckling curve, P/A versus L/r, for a column that has a bilinear stress–strain curve in compression as shown.
If the bolt length is 220 mmmm and the sleeve length is 200 mmmm, determine the tension in the bolt when a force of 50 kNkN is applied to the brackets. Express your answer to three significant figures and include appropriate units. Given: The bolt AB in (Figure 1) has a diameter of 21 mmmm and passes through a sleeve that has an inner diameter of 42 mmmm and an outer diameter of 52 mmmm. The bolt and sleeve are made of A-36 steel and are secured to the rigid brackets as shown.
A steel rod of diameter D = 50 mm has a tensile yield strength of 345 MPa supports an axial load P = 50 kN and a vertical load R = 2 kN acting at the end of an 0.8 m long arm. Calculate the strength factor of safety using (a) the maximum normal stress theory, (b) the maximum shear stress theory and (c) the distortion energy theory.
A ladder with a uniform cross-section has a length of 4.80-foot long. It weighs W Ib. It is arranged such that one end is on the ground and the other against a vertical wall. The angle of triction at all contact surtaces is 20 degrees. What is the value of the coefficient of triction? What is f, in terms of variable Na? What is the normal force at A in terms of variable W? Answer in three decimal places