Concept explainers
You are standing on a train platform watching a high-speed train pass by. A light inside one of the train cars is turned on and then a little later it is turned off. (a) Who can measure the proper time interval for the duration of the light: you or a passenger on the train? (b) Who can measure the proper length of the train car: you or a passenger on the train? (c) Who can measure the proper length of a sign attached to a post on the train platform: you or a passenger on the train? In each case explain your answer.
(a)
Whether passenger on train or observer in platform measures Proper time
Explanation of Solution
The relative velocity between passenger and train is zero, time measured by passenger in train is the proper time.
Conclusion: The time measured from frame where the relative velocity between two events is zero is called the proper time. Proper time is measured from frame where there is no relative motion between events.
(b)
Passenger on train or observer in platform measures the proper length.
Explanation of Solution
The Proper length is the length measured by observer at rest in his own frame. The relative velocity between passenger and train is zero, time measured by passenger in train is the proper time Since the passenger in train is at rest in his own frame, he can measure proper length of train Since the sign is attached to ground ,relative velocity between observer in platform and ground is zero, he measures the proper length of sign.
Conclusion: Proper length is measured from frame where there is no relativity between events.
(c)
Whether observer on platform or passenger on train measures proper length of sign post attached to ground.
Explanation of Solution
The time measured from frame where the relative velocity between two events is zero is called the proper time. The relative velocity between observer on platform and sign post is zero, time measured by observer on platform is the proper time.
Conclusion: Proper length is measured from frame where there is no relative motion between events.
Want to see more full solutions like this?
Chapter 37 Solutions
University Physics with Modern Physics, Volume 1 (Chs. 1-20) (14th Edition)
Additional Science Textbook Solutions
Chemistry: The Central Science (14th Edition)
Campbell Essential Biology with Physiology (5th Edition)
Applications and Investigations in Earth Science (9th Edition)
Biology: Life on Earth (11th Edition)
Campbell Biology: Concepts & Connections (9th Edition)
Campbell Biology (11th Edition)
- Find the total capacitance in micro farads of the combination of capacitors shown in the figure below. HF 5.0 µF 3.5 µF №8.0 μLE 1.5 µF Ι 0.75 μF 15 μFarrow_forwardthe answer is not 0.39 or 0.386arrow_forwardFind the total capacitance in micro farads of the combination of capacitors shown in the figure below. 2.01 0.30 µF 2.5 µF 10 μF × HFarrow_forward
- I do not understand the process to answer the second part of question b. Please help me understand how to get there!arrow_forwardRank the six combinations of electric charges on the basis of the electric force acting on 91. Define forces pointing to the right as positive and forces pointing to the left as negative. Rank in increasing order by placing the most negative on the left and the most positive on the right. To rank items as equivalent, overlap them. ▸ View Available Hint(s) [most negative 91 = +1nC 92 = +1nC 91 = -1nC 93 = +1nC 92- +1nC 93 = +1nC -1nC 92- -1nC 93- -1nC 91= +1nC 92 = +1nC 93=-1nC 91 +1nC 92=-1nC 93=-1nC 91 = +1nC 2 = −1nC 93 = +1nC The correct ranking cannot be determined. Reset Help most positivearrow_forwardPart A Find the x-component of the electric field at the origin, point O. Express your answer in newtons per coulomb to three significant figures, keeping in mind that an x component that points to the right is positive. ▸ View Available Hint(s) Eoz = Η ΑΣΦ ? N/C Submit Part B Now, assume that charge q2 is negative; q2 = -6 nC, as shown in (Figure 2). What is the x-component of the net electric field at the origin, point O? Express your answer in newtons per coulomb to three significant figures, keeping in mind that an x component that points to the right is positive. ▸ View Available Hint(s) Eoz= Η ΑΣΦ ? N/Carrow_forward
- 1. A charge of -25 μC is distributed uniformly throughout a spherical volume of radius 11.5 cm. Determine the electric field due to this charge at a distance of (a) 2 cm, (b) 4.6 cm, and (c) 25 cm from the center of the sphere. (a) = = (b) E = (c)Ẻ = = NC NC NCarrow_forward1. A long silver rod of radius 3.5 cm has a charge of -3.9 ис on its surface. Here ŕ is a unit vector ст directed perpendicularly away from the axis of the rod as shown in the figure. (a) Find the electric field at a point 5 cm from the center of the rod (an outside point). E = N C (b) Find the electric field at a point 1.8 cm from the center of the rod (an inside point) E=0 Think & Prepare N C 1. Is there a symmetry in the charge distribution? What kind of symmetry? 2. The problem gives the charge per unit length 1. How do you figure out the surface charge density σ from a?arrow_forward1. Determine the electric flux through each surface whose cross-section is shown below. 55 S₂ -29 S5 SA S3 + 9 Enter your answer in terms of q and ε Φ (a) s₁ (b) s₂ = -29 (C) Φ զ Ερ (d) SA = (e) $5 (f) Sa $6 = II ✓ -29 S6 +39arrow_forward
- No chatgpt pls will upvotearrow_forwardthe cable may break and cause severe injury. cable is more likely to break as compared to the [1] ds, inclined at angles of 30° and 50° to the vertical rings by way of a scaled diagram. [4] I 30° T₁ 3cm 3.8T2 cm 200 N 50° at it is headed due North and its airspeed indicat 240 km/h. If there is a wind of 100 km/h from We e relative to the Earth? [3]arrow_forwardCan you explain this using nodal analysis With the nodes I have present And then show me how many KCL equations I need to write, I’m thinking 2 since we have 2 dependent sourcesarrow_forward
- Principles of Physics: A Calculus-Based TextPhysicsISBN:9781133104261Author:Raymond A. Serway, John W. JewettPublisher:Cengage LearningPhysics for Scientists and Engineers: Foundations...PhysicsISBN:9781133939146Author:Katz, Debora M.Publisher:Cengage LearningModern PhysicsPhysicsISBN:9781111794378Author:Raymond A. Serway, Clement J. Moses, Curt A. MoyerPublisher:Cengage Learning
- College PhysicsPhysicsISBN:9781305952300Author:Raymond A. Serway, Chris VuillePublisher:Cengage LearningPhysics for Scientists and Engineers, Technology ...PhysicsISBN:9781305116399Author:Raymond A. Serway, John W. JewettPublisher:Cengage LearningCollege PhysicsPhysicsISBN:9781285737027Author:Raymond A. Serway, Chris VuillePublisher:Cengage Learning