BIO SPIDERWEB CONDUCTIVITY . Some types of spiders build webs that consist of threads made of dry silk coated with a solution of a variety of compounds. This coating leaves the threads, which are used to capture prey, hygroscopic —that is, they attract water from the atmosphere. It has been hypothesized that this aqueous coating makes the threads good electrical conductors. To test the electrical properties of coated thread, researchers placed a 5-mm length of thread between two electrical contacts* The researchers stretched the thread in 1-mm increments to more than twice its original length, and then allowed it to return to its original length, again in 1-mm increments. Some of the resistance measurements are shown in the table: *Based on F. Vollrath and D. Edmonds. “Consequences of electrical conductivity in an orb spider’s capture web.” Natunvissenschaften (100:12. December 2013, pp. 1163-69). 25.81 What is the maximum current that flows in the thread during this experiment if the voltage source is a 9-V battery? (a) about 1 A: (b) about 0.1 A: (c) about 1 µ A: (d) about 1 nA.
BIO SPIDERWEB CONDUCTIVITY . Some types of spiders build webs that consist of threads made of dry silk coated with a solution of a variety of compounds. This coating leaves the threads, which are used to capture prey, hygroscopic —that is, they attract water from the atmosphere. It has been hypothesized that this aqueous coating makes the threads good electrical conductors. To test the electrical properties of coated thread, researchers placed a 5-mm length of thread between two electrical contacts* The researchers stretched the thread in 1-mm increments to more than twice its original length, and then allowed it to return to its original length, again in 1-mm increments. Some of the resistance measurements are shown in the table: *Based on F. Vollrath and D. Edmonds. “Consequences of electrical conductivity in an orb spider’s capture web.” Natunvissenschaften (100:12. December 2013, pp. 1163-69). 25.81 What is the maximum current that flows in the thread during this experiment if the voltage source is a 9-V battery? (a) about 1 A: (b) about 0.1 A: (c) about 1 µ A: (d) about 1 nA.
BIO SPIDERWEB CONDUCTIVITY. Some types of spiders build webs that consist of threads made of dry silk coated with a solution of a variety of compounds. This coating leaves the threads, which are used to capture prey, hygroscopic—that is, they attract water from the atmosphere. It has been hypothesized that this aqueous coating makes the threads good electrical conductors. To test the electrical properties of coated thread, researchers placed a 5-mm length of thread between two electrical contacts* The researchers stretched the thread in 1-mm increments to more than twice its original length, and then allowed it to return to its original length, again in 1-mm increments. Some of the resistance measurements are shown in the table:
*Based on F. Vollrath and D. Edmonds. “Consequences of electrical conductivity in an orb spider’s capture web.” Natunvissenschaften (100:12. December 2013, pp. 1163-69).
25.81 What is the maximum current that flows in the thread during this experiment if the voltage source is a 9-V battery? (a) about 1 A: (b) about 0.1 A: (c) about 1 µA: (d) about 1 nA.
Some types of spiders build webs that consist of threads made of dry silk coated with a solution of a variety of compounds. This coating leaves the threads, which are used to capture prey, hygroscopic—that is, they attract water from the atmosphere. It has been hypothesized that this aqueous coating makes the threads good electrical conductors. To test the electrical properties of coated thread, researchers placed a 5-mm length of thread between two electrical contacts. The researchers stretched the thread in 1-mm increments to more than twice its original length, and then allowed it to return to its original length, again in 1-mm increments. Some of the resistance measurements are shown in the table:
(a) What is the best explanation for the behavior exhibited in the data?
(b) If the conductivity of the thread results from the aqueous coating only, how does the cross-sectional area of the coating compare when the thread is 13 mm long versus the starting length of 5 mm? Assume that the…
Good conductors of electricity, such as metals, are typically good conductors of heat; insulators, such as wood, are typically poor conductors of heat. Explain why there is a relationship between conduction of electricity and conduction of heat in these materials.
You are working in a laboratory, using very sensitive measurement equipment. Your supervisor has explained that the equipment is also very sensitive to electrical discharge from human operators. Specification tables for the equipment indicate that an electrical discharge providing even a very small amount of energy of 250 μJ is enough to damage the equipment. Your supervisor wants to install an apparatus that will be used to remove the electrical charge from individuals’ bodies before they touch the equipment. To do this, she asks you to estimate (a) the capacitance of the human body and determine (b) the charge on the body and (c) the electric potential of the body, relative to a point infinitely far away, corresponding to the energy transfer that will damage the equipment.
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, physics and related others by exploring similar questions and additional content below.