Circular Motion in a Magnetic Field Problem Help

  • Thread starter Enigma77
  • Start date
  • #1
Enigma77
2
0
When a particle with electric charge q moves with speed v in a plane perpendicular to a magnetic field B, there is a magnetic force at right angles to the motion with magnitude qvB, and the particle moves in a circle of radius r. This formula for the magnetic force is correct even if the speed is comparable to the speed of light. Show that p = qBr even if velocity is comparible to c. Remember that F does not equal m*a at very high speeds.

Ive been working trying to solve this problem for several hours so I think I need some help. I've been trying to use the momentum principle, p(final) = p(initial) + F*t. Can anyone offer some help or advice?
 

Answers and Replies

  • #2
Astronuc
Staff Emeritus
Science Advisor
20,992
5,049
Why would one use "p(final) = p(initial) + F*t."

Think of angular momentum. If the charge does not radiate, nor collides with another particle, then it has constant angular momentum.

When a particle moves with a relativistic velocity, what correction is applied to the mass? What about the magnetic field?

Think about the formula for angular momentum.
 

Suggested for: Circular Motion in a Magnetic Field Problem Help

  • Last Post
Replies
6
Views
347
Replies
7
Views
545
  • Last Post
Replies
6
Views
158
Replies
14
Views
526
Replies
14
Views
562
  • Last Post
Replies
4
Views
206
Replies
6
Views
443
  • Last Post
Replies
18
Views
512
  • Last Post
Replies
5
Views
540
Replies
8
Views
226
Top