
Using the property indicated in Prob. 7.124, determine the curve assumed by a cable of span L and sag h carrying a distributed load w = w0 cos (πx/L), where x is measured from mid-span. Also determine the maximum and minimum values of the tension in the cable.
PROBLEM 7.124 Show that the curve assumed by a cable that carries a distributed load w(x) is defined by the differential equation d2y/dx2 = w(x)/T0, where T0 is the tension at the lowest point.

The expression for the curve made by the cable, maximum and minimum values of the tension in the cable.
Answer to Problem 7.125P
The curve represented by the cable is
Explanation of Solution
The figure 1 below shows the cable and which makes the curve due the load w.
Write the expression for the load distributed.
Refer the problem 77268-7.4-7.124P and writhe the differential equation for the curve.
Write the expression for the differential equation for the curve.
Substitute
Integrate both side of the above equation and apply the condition
Integrate the above equation and apply the condition
Here C is the integration constant.
Apply the condition
Substitute
At
Substitute
The value of y at
Rewrite the above equation in terms of h.
Here
Therefore the minimum tension on the cable is
To find the maximum tension on the cable the slope of the above equation for y at
Here
Substitute
Rewrite the above equation in terms of
Write the expression to calculate the maximum tension on the cable.
Here
Substitute
Conclusion:
Thus, the curve represented by the cable is
Want to see more full solutions like this?
Chapter 7 Solutions
Vector Mechanics for Engineers: Statics
- P3: A differential band brake shown in the figure below uses a woven lining having a design value of the friction coefficient f=0.20. Dimensions are b=80 mm, r=250 mm, c=700 mm, a = 150 mm, s=35 mm, and 0=240°. Find 1) the brake torque if the maximum lining pressure is 0.5 MPa, 2) the corresponding actuating force F, and 3) the values of dimensions that would cause the brake to be self-locking. (25%) -240° F-250 mm Band width, b-80 mm Rotation Friction coefficient, -0.20 Maximum lining pressure, P-0.5 MPa 3-35 mm la-150 mm e-700 mm-arrow_forwardInclude a grapharrow_forwardA particular furnace is shaped like a section of a cone. The top surface of the furnace is uniformly heated by a resistance heater. During operation, the top surface is measured to be 800 K and the power supplied to the resistance heater is 1750 W/m². The sidewall of the furnace is perfectly insulated with ε = 0.2. If the emissivity of the top and bottom surfaces are ε = 0.5 and > = 0.7, respectively, determine the temperatures of the sidewall and the bottom surface of the furnace. A1 D₂ = 20 mm A₂ L = 50 mm D₁ = 40 mmarrow_forward
- You are designing an industrial furnace to keep pieces of sheet metal at a fixed temperature. You decide a long, hemispherical furnace will be the best choice. The hemispherical portion is built from insulating brick to reflect the radiation from a ceramic plate onto the sheet metal and the ceramic plate is heated by gas burners from below. An insulating wall prevents direct transmission of radiative energy from the ceramic plate to the sheet metal. The radius of the hemisphere is 1 m and the rest of the system properties can be found in the table below. You may neglect convection during your analysis. Temperature Emissivity Ceramic Plate 1600 K ε = 0.85 Sheet Metal 500 K Insulating Brick unknown € = 1 ε = 0.6 a) Calculate the required heat input, in W, per unit length of the furnace (out of the page) that must be supplied by the gas burners to maintain the specified temperatures. b) What is the temperature of the insulating brick surface? Metal products (2) T₂ = 500 K, &- 1 -…arrow_forwardDerive common expressions for the radiative heat transfer rate between two surfaces below. Aσ (T-T) a) Infinite parallel plates: A1, T1 E1 912 = 1 1 + ε1 E2 1 A2, T2, E2 b) Infinitely long concentric cylinders: 912 c) Concentric spheres: 912 182 A₁σ (T-T) 1-82 (11) = 1 + ε1 E2 = A₁σ (T-T) 1 1-82 રંતુ + E2 2arrow_forwardFollowing page contains formulas.arrow_forward
- 1) The assembly is made of the slender rods that have a mass per unit length of 3 kg/m. Determine the mass moment of inertia of the assembly about an axis perpendicular to the page and passing through point O. 0.4 m 0.8 m 0.4 marrow_forwardanswer asaparrow_forwardA radio controlled aircraft is instrumented with an airspeed sensor and a power module, which measures the airspeed V [m/s] with an uncertainty of ± 0.8 [m/s], the battery voltage E [V] with an uncertainty of ± 0.8 [V] and the current draw i with an uncertainty of ± 0.8 [A]. These sensors are used to estimate the coefficient of drag CD of the aircraft. For this purpose, the aircraft was flown under cruise condition at a constant speed, maintaining a constant altitude and the airspeed was recorded as V=10 [m/s]. A battery voltage of E=11.1 [V] and current draw i= 1[A] was also recorded. Prior to take off the weight of the aircraft was recorded using a scale as 0.8 [N] ± 0.03 [N], and the planform area S of the aircraft was found using a CAD model as 0.35 [m^2]. The air density p relevant to flight conditions was found to be p =1.225 [kg/m^3] and the propulsion efficiency was found to be 0.4. The coefficient of drag CD for cruise flight is governed by the following equation. Provide the…arrow_forward
- The structure of a house is such that it loses heat at a rate of 4500 kJ/h per °C difference between the indoors and outdoors. A heat pump that requires a power input of 5.50 kW is used to maintain this house at 24°C. Determine the lowest outdoor temperature for which the heat pump can meet the heating requirements of this house. (Include a minus sign if necessary.) The lowest outdoor temperature for which the heat pump can meet the heating requirements of this house is ________ °C.arrow_forwardAnnealing is an important step in many manufacturing processes, especially for metals. A particular manufacturing process requires annealing of a thin metallic sheet at 700°C. To accomplish this task, the sheet is placed in a large furnace, the walls of which are at approximately 730°C. An inert gas circulates through the oven to prevent oxidation of the metal. a) The metallic sheet can be approximated as diffuse, and the spectral emissivity of the sheet is shown in the figure. Determine the emissive power (W/m²) from the sheet when it is at a uniform T = 700°C. b) Determine the net rate of radiative flux (W/m²) to the metal sheet. (Note that the irradiance depends on the oven wall temperature, not the sheet temperature). 1 0.8 0.3 2.5 λ (μη) . c) The circulating inert gas comes from a reservoir and must be preheated before it flows into the furnace so that it doesn't cool the sheet too much. The anticipated convection coefficient between the sheet and the gas is h = 150 W/m² K. What…arrow_forward5. For a gauge pressure at A in the figure shown which is equal to -1.58 psi and the specific gravity of liquid B = 1.00, find the pressure at pt. B. 10.50 ft Air 11.25 ft 9.00 10.00 ft Liquid B =1.60arrow_forward
- International Edition---engineering Mechanics: St...Mechanical EngineeringISBN:9781305501607Author:Andrew Pytel And Jaan KiusalaasPublisher:CENGAGE LPrinciples of Heat Transfer (Activate Learning wi...Mechanical EngineeringISBN:9781305387102Author:Kreith, Frank; Manglik, Raj M.Publisher:Cengage LearningMechanics of Materials (MindTap Course List)Mechanical EngineeringISBN:9781337093347Author:Barry J. Goodno, James M. GerePublisher:Cengage Learning


