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--- 184_notes:q_path [2020/08/23 21:28] – dmcpadden
+++ 184_notes:q_path [2021/07/07 14:37] (current) – schram45
@@ Line 6: / Line 6: @@
 ===== Path of a Charge through a Magnetic Field =====
-We just talked about the force that a moving charge feels when it travels through a magnetic field. So now the question remains: what happens to the charge when it feels this force? Since the magnetic force is perpendicular to the velocity of the charge, we will show that the charge actually begins to move in a circular pattern.
+We just talked about the force that a moving charge feels when it travels through a magnetic field. So now the question remains: what happens to the charge when it feels this force? Since the magnetic force is perpendicular to the velocity of the charge, **we will show that the charge actually begins to move in a circular pattern.**
 {{youtube>IXc5feWSxsE?large}}
-==== Path of the Moving Charge ====
+===== Path of the Moving Charge =====
 [{{  184_notes:week11_3.png?150|Force felt by a charge moving through a B field in the -x direction}}]
@@ Line 22: / Line 22: @@
-==== Work Done ====
+===== Work Done =====
 [{{  184_notes:week11_5.png?400|Trajectory of a particle moving through a constant magnetic field at a constant speed}}]
@@ Line 31: / Line 31: @@
 Since the dot product is between the magnetic force and the path direction, and because those vectors are perpendicular, this tells us that **the work done by the magnetic field is actually zero**.
  $W_{B}=0$
-This is an important result because this tells us that there is no change in the energy of the particle. In other words, the magnetic force **only changes the direction of the moving charge - it does not slow down or speed up as it travels through the magnetic field** (unless there is a non-magnetic force also acting on it). The magnetic field can only turn a charge not accelerate it.
+This is an important result because this tells us that **there is no change in the energy of the particle.** In other words, the magnetic force **only changes the direction of the moving charge - it does not slow down or speed up as it travels through the magnetic field** (unless there is a non-magnetic force also acting on it). The magnetic field can only turn a charge not accelerate it.
 This also means that we do not have a way to define a magnetic potential or a magnetic potential energy in the same way that we did with electric fields. It turns out that we can define a [[https://en.wikipedia.org/wiki/Vector_potential|vector potential]], which you may talk about in your future courses.
-==== Examples ====
+===== Examples =====
-[[:184_notes:examples:Week10_radius_motion_B_field|Radius of Circular Motion in a Magnetic Field]]
+  * [[:184_notes:examples:Week10_radius_motion_B_field|Radius of Circular Motion in a Magnetic Field]]
+  * [[:184_notes:examples:Week10_helix|Helical Motion in a Magnetic Field]]
-[[:184_notes:examples:Week10_helix|Helical Motion in a Magnetic Field]]
+    * Video Example: Helical Motion in a Magnetic Field
+{{youtube>wTrsMULWjaM?large}}