Concept explainers
Explain why birds can sit on power lines safely, whereas leaning a metal ladder up against a power line to fetch a stuck kite is extremely dangerous.
The reason why it is safe for the birds to sit on the power lines, but leaning a metal ladder against a power line is extremely dangerous.
Answer to Problem 1Q
The resistance of the bird is larger compared to the resistance of the wire between the bird’s feet, so that a very little current passes through the bird as it sits on the power line.
A metal ladder leaned against a power line will have a direct contact between the high potential line and ground which implies person standing on the ladder will have a larger potential difference between his hand and feet which produces large current through the person’s body large enough to cause substantial damage.
Explanation of Solution
Even though the bird’s feet are at high potential compared to the ground, the potential difference between the feet of the bird is very little since they are close together on the wire. And also the resistance of the bird is much greater when compared to the resistance of the wire between the bird’s feet. These two resistance are in parallel so that only a very little current will pass through the bird when it sits on the transmission line.
A metal ladder leaned against a power line will have a direct contact to the high potential line and ground so that the person standing on the ladder will have a larger potential difference between his hand and feet.
Even if the person’s resistance is large, the potential difference will also be so large to produce current through the person’s body large enough to cause severe damage or death.
Therefore, it is safe for the birds to sit on the power lines, but leaning a metal ladder against a power line is extremely dangerous.
Want to see more full solutions like this?
Chapter 26 Solutions
Physics for Scientists and Engineers with Modern Physics
Additional Science Textbook Solutions
Chemistry: A Molecular Approach (4th Edition)
Physics for Scientists and Engineers: A Strategic Approach, Vol. 1 (Chs 1-21) (4th Edition)
Introductory Chemistry (6th Edition)
Microbiology: An Introduction
College Physics: A Strategic Approach (3rd Edition)
Microbiology with Diseases by Body System (5th Edition)
- The drawing shows an edge-on view of two planar surfaces that intersect and are mutually perpendicular. Surface (1) has an area of 1.90 m², while surface (2) has an area of 3.90 m². The electric field in the drawing is uniform and has a magnitude of 215 N/C. Find the magnitude of the electric flux through surface (1 and 2 combined) if the angle 8 made between the electric field with surface (2) is 30.0°. Solve in Nm²/C 1 Ө Surface 2 Surface 1arrow_forwardPROBLEM 5 What is the magnitude and direction of the resultant force acting on the connection support shown here? F₁ = 700 lbs F2 = 250 lbs 70° 60° F3 = 700 lbs 45° F4 = 300 lbs 40° Fs = 800 lbs 18° Free Body Diagram F₁ = 700 lbs 70° 250 lbs 60° F3= = 700 lbs 45° F₁ = 300 lbs 40° = Fs 800 lbs 18°arrow_forwardPROBLEM 3 Cables A and B are Supporting a 185-lb wooden crate. What is the magnitude of the tension force in each cable? A 20° 35° 185 lbsarrow_forward
- The determined Wile E. Coyote is out once more to try to capture the elusive Road Runner of Loony Tunes fame. The coyote is strapped to a rocket, which provide a constant horizontal acceleration of 15.0 m/s2. The coyote starts off at rest 79.2 m from the edge of a cliff at the instant the roadrunner zips by in the direction of the cliff. If the roadrunner moves with constant speed, find the minimum velocity the roadrunner must have to reach the cliff before the coyote. (proper sig fig in answer)arrow_forwardPROBLEM 4 What is the resultant of the force system acting on the connection shown? 25 F₁ = 80 lbs IK 65° F2 = 60 lbsarrow_forwardThree point-like charges in the attached image are placed at the corners of an equilateral triangle as shown in the figure. Each side of the triangle has a length of 38.0 cm, and the point (C) is located half way between q1 and q3 along the side. Find the magnitude of the electric field at point (C). Let q1 = −2.80 µC, q2 = −3.40 µC, and q3 = −4.50 µC. Thank you.arrow_forward
- STRUCTURES I Homework #1: Force Systems Name: TA: PROBLEM 1 Determine the horizontal and vertical components of the force in the cable shown. PROBLEM 2 The horizontal component of force F is 30 lb. What is the magnitude of force F? 6 10 4 4 F = 600lbs F = ?arrow_forwardThe determined Wile E. Coyote is out once more to try to capture the elusive Road Runner of Loony Tunes fame. The coyote is strapped to a rocket, which provide a constant horizontal acceleration of 15.0 m/s2. The coyote starts off at rest 79.2 m from the edge of a cliff at the instant the roadrunner zips by in the direction of the cliff. If the roadrunner moves with constant speed, find the minimum velocity the roadrunner must have to reach the cliff before the coyote. (proper sig fig)arrow_forwardHello, I need some help with calculations for a lab, it is Kinematics: Finding Acceleration Due to Gravity. Equations: s=s0+v0t+1/2at2 and a=gsinθ. The hypotenuse,r, is 100cm (given) and a height, y, is 3.5 cm (given). How do I find the Angle θ1? And, for distance traveled, s, would all be 100cm? For my first observations I recorded four trials in seconds: 1 - 2.13s, 2 - 2.60s, 3 - 2.08s, & 4 - 1.95s. This would all go in the coloumn for time right? How do I solve for the experimental approximation of the acceleration? Help with trial 1 would be great so I can use that as a model for the other trials. Thanks!arrow_forward
- After the countdown at the beginning of a Mario Kart race, Bowser slams on the gas, taking off from rest. Bowser get up to a full speed of 25.5 m/s due to an acceleration of 10.4 m/s2. A)How much time does it take to reach full speed? B) How far does Bowser travel while accelerating?arrow_forwardThe drawing in the image attached shows an edge-on view of two planar surfaces that intersect and are mutually perpendicular. Side 1 has an area of 1.90 m^2, Side 2 has an area of 3.90 m^2, the electric field in magnitude is around 215 N/C. Please find the electric flux magnitude through side 1 and 2 combined if the angle (theta) made between the electric field with side 2 is 30.0 degrees. I believe side 1 is 60 degrees but could be wrong. Thank you.arrow_forwardAfter the countdown at the beginning of a Mario Kart race, Bowser slams on the gas, taking off from rest. Bowser get up to a full speed of 25.5 m/s due to an acceleration of 10.4 m/s2.arrow_forward
- Physics for Scientists and Engineers: Foundations...PhysicsISBN:9781133939146Author:Katz, Debora M.Publisher:Cengage LearningCollege PhysicsPhysicsISBN:9781305952300Author:Raymond A. Serway, Chris VuillePublisher:Cengage LearningCollege PhysicsPhysicsISBN:9781938168000Author:Paul Peter Urone, Roger HinrichsPublisher:OpenStax College
- Principles of Physics: A Calculus-Based TextPhysicsISBN:9781133104261Author:Raymond A. Serway, John W. JewettPublisher:Cengage LearningPhysics for Scientists and Engineers, Technology ...PhysicsISBN:9781305116399Author:Raymond A. Serway, John W. JewettPublisher:Cengage LearningGlencoe Physics: Principles and Problems, Student...PhysicsISBN:9780078807213Author:Paul W. ZitzewitzPublisher:Glencoe/McGraw-Hill