Velocity of a Proton in a Capacitor

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SUMMARY

The discussion focuses on calculating the trajectory of a proton fired horizontally at a speed of 1.1 x 106 m/s through a parallel-plate capacitor with an electric field of 1.3 x 105 V/m. The proton enters the capacitor 18.6 mm above the lower plate, and the acceleration due to the electric field is determined to be 1.245 x 1013 m/s2. The voltage difference across the plates is 4030 V. The key takeaway is that the horizontal acceleration is zero while the vertical acceleration is directed downward due to the electric field.

PREREQUISITES
  • Understanding of kinematics equations
  • Knowledge of electric fields and forces on charged particles
  • Familiarity with parallel-plate capacitor configurations
  • Basic principles of projectile motion
NEXT STEPS
  • Calculate the time taken for the proton to travel through the capacitor
  • Determine the vertical displacement of the proton using kinematics
  • Explore the effects of varying electric field strengths on particle trajectories
  • Investigate the relationship between voltage and electric field in capacitors
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Students studying physics, particularly those focusing on electromagnetism and kinematics, as well as educators looking for practical examples of charged particle motion in electric fields.

Phoenixtears
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Homework Statement



A proton is fired horizontally with a speed of 1.1 106 m/s through the parallel-plate capacitor shown in Figure P34.37. The capacitor's electric field is = (1.3 105 V/m, down) and the distance between the plates is 31 millimeter.
(Image Attached)


The proton entered the capacitor gap 18.6 milli-meters above the lower plate. Where doe the proton strike the lower plate?

Measured in meters from the front edge of the lower plate.

Homework Equations



Kinematics Equations

The Attempt at a Solution



There were other questions on this problem that I already solved for. So here are other things that I know:

The magnitude of the acceleration= 1.245E13 m/s/s

Voltage difference= 4030 V


Now I've set up a kinematics table (separate for horizontal and vertical):

Known for horizontal: Initial V= 1.1E6; A= 1.245E13
Uknown: distance, final velocity, time

Known for vertical: x= .0186 meters; Initial v= 0
Uknown: final velocity, acceleration, time


Any suggestions? I've no idea where to go from here.

Thanks in advance!

~Phoenix
 

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Hi Phoenixtears,

Phoenixtears said:

Homework Statement



A proton is fired horizontally with a speed of 1.1 106 m/s through the parallel-plate capacitor shown in Figure P34.37. The capacitor's electric field is = (1.3 105 V/m, down) and the distance between the plates is 31 millimeter.
(Image Attached)


The proton entered the capacitor gap 18.6 milli-meters above the lower plate. Where doe the proton strike the lower plate?

Measured in meters from the front edge of the lower plate.

Homework Equations



Kinematics Equations

The Attempt at a Solution



There were other questions on this problem that I already solved for. So here are other things that I know:

The magnitude of the acceleration= 1.245E13 m/s/s

Since the electric field is downwards, what is the direction of this acceleration? I think the answer for this will change your kinematics table below.


Voltage difference= 4030 V


Now I've set up a kinematics table (separate for horizontal and vertical):

Known for horizontal: Initial V= 1.1E6; A= 1.245E13
Uknown: distance, final velocity, time

Known for vertical: x= .0186 meters; Initial v= 0
Uknown: final velocity, acceleration, time


Any suggestions? I've no idea where to go from here.

Thanks in advance!

~Phoenix
 


Aha! I see. That makes so much more sense.

Becasue the field is down, the acceleration is also down. Then the horizonatal acceleration is 0 (I should have listened to my sister :-P). Thank you so much!
 


Phoenixtears said:
Aha! I see. That makes so much more sense.

Becasue the field is down, the acceleration is also down. Then the horizonatal acceleration is 0 (I should have listened to my sister :-P). Thank you so much!

Sure, glad to help!
 

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