![Physics for Scientists and Engineers: Foundations and Connections](https://www.bartleby.com/isbn_cover_images/9781133939146/9781133939146_largeCoverImage.gif)
Concept explainers
Cosmic rays are high-energy charged particles produced by astronomical objects. Many of the cosmic rays that make their way to the Earth are trapped by the Earth’s magnetic field and never reach the surface. These trapped cosmic rays are found in the Van Allen belts—donut-shaped zones over the Earth’s equator (Fig. 30.34). These cosmic rays are mostly protons with energies of about 30 MeV. The inset in the figure shows a cosmic ray proton as it is about to enter the Earth’s magnetic field. The cosmic ray’s velocity is initially perpendicular to the field. Three students discuss what happens to the incoming cosmic ray. Decide which student or students are correct.
Figure 30.34 The Van Allen belts are donut-shaped zones of trapped cosmic rays above the Earth’s surface. Inset: What happens to this cosmic ray as it enters the Earth’s magnetic field?
Shannon: The velocity is perpendicular to the magnetic field, so the cosmic ray just passes through the field and hits the Earth’s atmosphere.
Avi: What you are saying is that the magnetic field exerts no force on the cosmic ray. Actually, it exerts a huge force because the velocity is perpendicular to the magnetic field. The force will be into the page.
Cameron: Avi is right. The cosmic ray proton is going to feel a huge magnetic force. Because it is positively charged, it will be pushed upward along the magnetic field lines.
Shannon: I never said the force was zero. There is a force, but the force is perpendicular to the magnetic field lines. In this case, that’s to the left—toward the Earth.
Avi: The force is perpendicular to the magnetic field, but it also has to be perpendicular to the velocity. Because
![Check Mark](/static/check-mark.png)
Want to see the full answer?
Check out a sample textbook solution![Blurred answer](/static/blurred-answer.jpg)
Chapter 30 Solutions
Physics for Scientists and Engineers: Foundations and Connections
- A proton and a helium nucleus (consisting of two protons and two neutrons) pass through a velocity selector and into a mass spectrometer. The radius of the protons circular path is rp. Find an expression for the radius r of the helium nucleuss path in terms of rp. (You may assume the mass of a proton is roughly equal to the mass of a neutron, and the helium nucleus has the same speed as the proton.)arrow_forwardA carbon-14 ion with a charge of +6.408x10^-19 C and a mass of 2.34x10^-26 kg is sent through a mass spectrometer and hits a detector at a point 10.0 cm to the left of where the beam leaves the velocity selector. The velocity selector and the detector are both in a region of magentic field of strength 0.500 T. What are the magnitude and direction of the electric field in the velocity selector where the particels travel in a straight line for 15.0 cm? Please also explain and show the steps you used to get there/the physics behind why/how you got to the answer to help me better understand. Thank you soo much. Also, the work and the explanation or most important because I already have the correct answer - I'm just unsure of how to get there.arrow_forwardA proton (carrying a positive charge) travels with speed 2.5x105 m/s to the right and enters between the two parallel charged plates. The electric field strength inside the two plates is 7.5x104 V/m. What magnetic field strength and direction will allow the proton to pass between the plates without being deflected? Vo +++ + O 1.9x1010 T, into the page O 1.9x1010 T, to the left 1.9x1010 T, out of page O 3.3 T, out of page O 3.3 T, to the left O 3.3 T, into the page O 0.30 T, out of page O 0.30 T, into the page O 0.30 T, to the leftarrow_forward
- A jet develops a 0.9 V potential difference between the tips of its wings when flying above a region of the earth where the earth's magnetic field points essentially vertically upward and has a strength of about 39 T (10-6 T). If the jet's wingspan is 35 m, what is its speed? Give your answer in km/s.arrow_forwardAn ion that is singly charged, q=1.602x1019 C, and has mass 2.3x1026 kg, enters the mass spectrometer shown right. The electric field has a value of 2,900 V/m while the magnetic field both inside and outside the velocity selector points into the page and has value of 0.060 T a) What will the value of the radius of the ion's obit be? B) In detector this layout would you be able to detect negatively charged ions? Why or why not?arrow_forwardA proton circulates in a cyclotron, beginning approximately at rest at the center. The electric potential difference between the dees is 400V. What is the proton's kinetic energy after completing 100 passes through the gap?arrow_forward
- investigate the speed and the kinetic energy of a proton as it passes through a perpendicular and homogenous magnetic field of 0.5 T, such that it has a circular orbit with a radius of 1 m. Find the speed and the kinetic energy of the proton in MeV. Show your calculations and provide an explanation of your solution. In an experiment with cosmic rays, a vertical beam of particles that have a charge magnitude of 5q (q = 1.6×10-19 C) and a mass 10 times the proton mass enters a uniform horizontal Magnetic field of 0.250 T and is bent in a semicircle of 95cm. Find the speed of the particle. Show your calculations and provide an explanation of your solution.arrow_forwardIn an experiment to measure the charge on electron, the electrons travelling at a speed of 1.825 × 107 m/s are subjected to a deflecting electric field 3.2 × 104 V/m. Determine the intensity of magnetic field applied so that the beam remains undeflected.arrow_forwardA proton is moving under the combined influence of an electric field (E = 1747 V/m) and a magnetic field (B = 1.37 T), as shown in the figure. Assuming the proton is moving in the direction shown in the figure with speed 229 m/s at the instant it enters the crossed fields, what is the acceleration of the proton? (in m/s^2)arrow_forward
- Consider two protons trapped on the same geomagnetic field line. One proton has kinetic energy 10 eV and the other has kinetic energy of 10 keV. Which statement about the magnetic field strength at their respective mirror points is correct? A. B10 eV < B10 keV B. B10 eV > B10 keV C. B10 eV = B10 keV D. Not enough information is givenarrow_forwardone gram of copper has 9.48x10^21 atoms, and each copper atom has 29 eletrons. what is the total charge of these electronsarrow_forwardA 3.5 mC charge moves with a speed of 10,000 m/s in a magnetic field of 0.5 T. How much force is exerted on the charge?arrow_forward
- Physics for Scientists and Engineers: Foundations...PhysicsISBN:9781133939146Author:Katz, Debora M.Publisher:Cengage LearningPrinciples of Physics: A Calculus-Based TextPhysicsISBN:9781133104261Author:Raymond A. Serway, John W. JewettPublisher:Cengage LearningPhysics for Scientists and Engineers with Modern ...PhysicsISBN:9781337553292Author:Raymond A. Serway, John W. JewettPublisher:Cengage Learning
- Physics for Scientists and EngineersPhysicsISBN:9781337553278Author:Raymond A. Serway, John W. JewettPublisher:Cengage Learning
![Text book image](https://www.bartleby.com/isbn_cover_images/9781133939146/9781133939146_smallCoverImage.gif)
![Text book image](https://www.bartleby.com/isbn_cover_images/9781133104261/9781133104261_smallCoverImage.gif)
![Text book image](https://www.bartleby.com/isbn_cover_images/9781337553292/9781337553292_smallCoverImage.gif)
![Text book image](https://www.bartleby.com/isbn_cover_images/9781938168161/9781938168161_smallCoverImage.gif)
![Text book image](https://www.bartleby.com/isbn_cover_images/9781337553278/9781337553278_smallCoverImage.gif)