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…
A Resistive Heater. You and your team are designing a small tube heater that consists of a small ceramic tube
wrapped with a special heater wire composed of Nichrome. When you run an electrical current through the wire, the
wire (and therefore the tube) heats up through resistive heating. Nichrome is an alloy composed of 80% nickel and
20% chromium, and has a resistivity of p = 1.25 × 10-602. m.
(a) What is the resistance per centimeter of 28-gauge Nichrome wire? ("28 gauge" means the wire has a diameter D=
0.320 mm)
(b) You wrap the tube with 41.0 cm of the Nichrome wire, and you want the power output of your heater to be 115
W. What current is needed?
(c) What voltage will provide the current calculated in (b)?
(a) Number
i
Units
(b) Number i
Units
(c) Number
Units
You heard a story that a person who fell from the sixth floor of a building was able to survive. The individual caught the wire of a copper electronic line. He wasn't electrocuted, although being in contact with an exposed live wire. The wire was able to reduce his speed before finally hitting the ground. Create a scientific explanation if such an event is possible or not.
Chapter 25 Solutions
University Physics with Modern Physics (14th Edition)
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.