
Choose the option from each pair that makes the following statement correct. According to an observer at rest, moving clocks run more [(a) slowly; (b) quickly] than stationary clocks and moving rods are [ (c) longer; (d) shorter] than stationary rods.

Answer to Problem 1CQ
According to an observer at rest, moving rods are (d) shorter than stationary rods.
Explanation of Solution
Time dilation: According to the theory of relativity, time dilation is a difference in the elapsed time measured by two observers, either due to a velocity difference relative to each other or by being differently situated relative to a gravitational field.
Length contraction: Length contraction is the phenomenon that a moving object’s length is measured to be shorter than its proper length, which is the length which is the length as measured in the object’s own rest frame.
Conclusion:
The time measured by the observer at the rest frame with the stationary clocks is the proper time. The proper time measured by the stationary clocks will be slower than the time measure in the moving clocks. Thus, the choice (b) is correct.
The time measured by the moving clocks will be shorter than the time measured by the stationary clocks according to the time dilation. Thus, the choice (a) is incorrect.
The length of the rod measured when it is at rest is its proper length. When the rod is moving with a speed near to the speed of light, the length will appear shorter according to the length contraction. Thus, the choice (d) is correct.
The length of a stationary rod measures according to the rest frame is longer compared to the moving rod with respect to the rest frame. Thus, the choice (c) is incorrect
Want to see more full solutions like this?
Chapter 26 Solutions
College Physics
- at a certain location the horizontal component of the earth’s magnetic field is 2.5 x 10^-5 T due north A proton moves eastward with just the right speed so the magnetic force on it balances its weight. Find the speed of the proton.arrow_forwardExample In Canada, the Earth has B = 0.5 mT, pointing north, 70.0° below the horizontal. a) Find the magnetic force on an oxygen ion (O) moving due east at 250 m/s b) Compare the |FB| to |FE| due to Earth's fair- weather electric field (150 V/m downward).arrow_forwardThree charged particles are located at the corners of an equilateral triangle as shown in the figure below (let q = 2.20 µC, and L = 0.810 m). Calculate the total electric force on the 7.00-µC charge. What is the magnitude , what is the direction?arrow_forward
- (a) Calculate the number of electrons in a small, electrically neutral silver pin that has a mass of 9.0 g. Silver has 47 electrons per atom, and its molar mass is 107.87 g/mol. (b) Imagine adding electrons to the pin until the negative charge has the very large value 2.00 mC. How many electrons are added for every 109 electrons already present?arrow_forward(a) Calculate the number of electrons in a small, electrically neutral silver pin that has a mass of 13.0 g. Silver has 47 electrons per atom, and its molar mass is 107.87 g/mol.arrow_forward8 Two moving charged particles exert forces on each other because each creates a magnetic field that acts on the other. These two "Lorentz" forces are proportional to vix (2 xr) and 2 x (vi x-r), where is the vector between the particle positions. Show that these two forces are equal and opposite in accordance with Newton's third law if and only if rx (vi × 2) = 0.arrow_forward
- 6 The force = +3 + 2k acts at the point (1, 1, 1). Find the torque of the force about (a) (b) the point (2, -1, 5). Careful about the direction of ŕ between the two points. the line = 21-+5k+ (i-+2k)t. Note that the line goes through the point (2, -1, 5).arrow_forward5 Find the total work done by forces A and B if the object undergoes the displacement C. Hint: Can you add the two forces first?arrow_forward1 F2 F₁ -F₁ F6 F₂ S A Work done on the particle as it moves through the displacement is positive. True False by the force Farrow_forward
- A student measuring the wavelength produced by a vapour lamp directed the lightthrough two slits with a separation of 0.20 mm. An interference pattern was created on the screen,3.00 m away. The student found that the distance between the first and the eighth consecutive darklines was 8.0 cm. Draw a quick picture of the setup. What was the wavelength of the light emittedby the vapour lamp?arrow_forwardA ball is tied to one end of a string. The other end of the string is fixed. The ball is set in motion around a vertical circle without friction. At the top of the circle, the ball has a speed of ; = √√ Rg, as shown in the figure. At what angle should the string be cut so that the ball will travel through the center of the circle? The path after string is cut Rarrow_forward(a) A luggage carousel at an airport has the form of a section of a large cone, steadily rotating about its vertical axis. Its metallic surface slopes downward toward the outside, making an angle of 24.5° with the horizontal. A 30.0-kg piece of luggage is placed on the carousel, 7.46 m from the axis of rotation. The travel bag goes around once in 37.5 s. Calculate the magnitude of the force of static friction between the bag and the carousel. Your response differs significantly from the correct answer. Rework your solution from the beginning and check each step carefully. N (b) The drive motor is shifted to turn the carousel at a higher constant rate of rotation, and the piece of luggage is bumped to a position 7.94 m from the axis of rotation. The bag is on the verge of slipping as it goes around once every 30.5 s. Calculate the coefficient of static friction between the bag and the carousel. Your response differs significantly from the correct answer. Rework your solution from the…arrow_forward
- Modern PhysicsPhysicsISBN:9781111794378Author:Raymond A. Serway, Clement J. Moses, Curt A. MoyerPublisher:Cengage LearningPhysics for Scientists and Engineers: Foundations...PhysicsISBN:9781133939146Author:Katz, Debora M.Publisher:Cengage LearningUniversity Physics Volume 3PhysicsISBN:9781938168185Author:William Moebs, Jeff SannyPublisher:OpenStax
- Principles of Physics: A Calculus-Based TextPhysicsISBN:9781133104261Author:Raymond A. Serway, John W. JewettPublisher:Cengage LearningClassical Dynamics of Particles and SystemsPhysicsISBN:9780534408961Author:Stephen T. Thornton, Jerry B. MarionPublisher:Cengage LearningCollege PhysicsPhysicsISBN:9781305952300Author:Raymond A. Serway, Chris VuillePublisher:Cengage Learning





