Acceleration of Protons in Magnetic Field and Induced Electric Field

[cesaravila]

Inside of circular region of radius 10cm shown in Figure 5(a) there is
a uniform magnetic fi eld pointing upwards and three protons held in
place: one at the center, one at a distance of 5cm from the center and
one at a distance 15cm from the center e there is no magnetic field.
The magnetic fi eld as a function of time is shown in Figure 5(b). At
t = 3s the three protons are released.

- Which protons, if any, experience an acceleration? Justify your
response.
- What is the direction of acceleration for those protons expected to accelerate?
- What is the magnitude of acceleration for those protons expected to accelerate?
-Will any of the protons follow a circular path? If yes, how do you
know? If not, why not?

SEE ATTACHED FIGURES

My attempt at a solution:

I believe that all of the protons will accelerate either due to the force by the field or the force by the induced electric field.

As for direction I am unsure but think that the proton in the center will pivot about its axis in the clockwise while the other proton in the field has circular motion in the clockwise. The proton outside of the field will flow counterclockwise in circular motion.

I am unsure how to calculate the magnitude of acceleration.

I believe all of the protons will experience circular motion.

 

[Simon Bridge]

Are you ignoring the electric force of the protons on each other?
You should know an equation that relates the changing B field with the force on a charge, and another equation that relates the force to the acceleration.