Many caterpillars construct cocoons from silk, one of the strongest naturally occurring materials known. Each thread is typically 2.0 µm in diameter, and the silk has a Young's modulus of 4.0 × 10⁹ N/m². Assuming that there is no appreciable space between the parallel strands, how many strands N would be needed to make a rope 8.2 m long that would stretch only 1.02 cm when supporting a pair of 91-kg mountain climbers? N = Again assuming that there is no appreciable space between the parallel strands, what would be the diameter d of the rope? strands d = cm

Many caterpillars construct cocoons from silk, one of the strongest naturally occurring materials known. Each thread is typically 2.0 µm in diameter, and the silk has a Young's modulus of 4.0 × 10⁹ N/m². Assuming that there is no appreciable space between the parallel strands, how many strands N would be needed to make a rope 8.2 m long that would stretch only 1.02 cm when supporting a pair of 91-kg mountain climbers? N = Again assuming that there is no appreciable space between the parallel strands, what would be the diameter d of the rope? strands d = cm

Physics for Scientists and Engineers

10th Edition

ISBN:9781337553278

Author:Raymond A. Serway, John W. Jewett

Publisher:Raymond A. Serway, John W. Jewett

Chapter12: Static Equilibrium And Elasticity

Section: Chapter Questions

Problem 27AP: The lintel of prestressed reinforced concrete in Figure P12.27 is 1.50 m long. The concrete encloses...

See similar textbooks

Similar questions

An aluminium (=2.7g/cm3) wire is suspended from the ceiling and hangs vertically. How long must the wire be before the stress at its upper end reaches the proportionality limit, which is 8.0107N/m2 ?
In Example 14.3, we found that one of the steel cables supporting an airplane at the Udvar-Hazy Center was under a tension of 9.30 103 N. Assume the cable has a diameter of 2.30 era and an initial length of 8.00 m before the plane is suspended on the cable. How much longer is the cable when the plane is suspended on it?
A steel cable 2.00 m in length and with cross-sectional radius 0.350 mm is used to suspend from the ceiling a 10.0-kg model aircraft that is flying in a horizontal circle with an angular speed of 6.00 rad/s. What is the strain produced in the cable?
Two rods, one made of copper and the other of steel, have the same dimensions. If the copper rod stretches by 0.15mm under some stress, how much does the steel rod stretch under the same stress?
A uniform wire (Y = 2.0 1011 N/m2) is subjected to a longitudinal tensile stress of 4.0 107 N/m2. What is the fractional change in the length of the wire?
Assume Youngs modulus for bone is 1.50 1010 N/m2. The bone breaks if stress greater than 1.50 108 N/m2 is imposed on it. (a) What is the maximum force that can be exerted on the femur bone in the leg if it has a minimum effective diameter of 2.50 cm? (b) If this much force is applied compressively, by how much does the 25.0-cm-long bone shorten?
Alarge uniform cylindrical steel rod of density =7.8g/cm3 is 2.0 m long and has a diameter of 5.0 cm. the rod is fastened to a concrete floor with its long axis vertical.what is the normal stress in the rod at the cross-section located at (a)1.0 mfrom its lower end?(b)1.5 m from the lower end?
A 90-kg mountain climber bangs from a nylon rope and stretches it by 25.0 cm. If the rope was originally 30.0 m bog and its diameter is 1.0 cm, is Young’s modulus for the nylon?
By how much does a 65.0kg mountain climber stretch her 0.800cm diameter nylon rope when she hangs 35.0m below a rock outcropping? (For nylon, Y=1.35109Pa. )
Some people modify cars to be much closer to the ground than when manufactured. Should they install stiffer springs? Explain your answer.
Review the relationship between stress and strain. Can you find any similarities between the two quantities?
A horizontal, rigid bar of negligible weight is fixed against a vertical wall at one end and supported by a vertical string at the other end. The bar has a length of 50.0 cm and is used to support a hanging block of weight 400.0 N from a point 30.0 cm from the wall as shown in Figure P14.81. The string is made from a material with a tensile strength of 1.2 108 N/m2. Determine the largest diameter of the string for which it would still break. FIGURE P14.81