Calculating Electron Trajectory in an Electric Field

In summary, an electron is accelerated towards a metal plate in a vacuum tube, passing through a metal grid with a potential of 180 Volts. The metal plate is 1.2 cm away and has a potential of -10.0 Volts. To find how close the electron gets to the plate, one can use the equation for work done which is equal to the change in potential energy. The work done is also related to the kinetic energy, which can be used to find the distance at which the electron stops. This can be done using the conservation of energy equation or the work-energy theorem.
  • #1
rhettfraser
4
0

Homework Statement


An electron is accelerated from the filament in a vacuum tube towards a metal grid which is maintained at a potential of 180 Volts. It goes through one of the holes in the grid and continues towards a metal plate 1.2 cm away which is maintained at a potential of -10.0 Volts.

How close to the plate does the electron get?


Homework Equations



Im not sure, maybe something to do with Potential Difference

The Attempt at a Solution



I don't know where to start
 
Physics news on Phys.org
  • #2
Welcome to PF!

Hi rhettfraser! Welcome to PF! :smile:

Hint: work done = ∫ force"dot"distance = ∫ electric-field"dot"charge, and the electron will stop when the KE is zero. :wink:
 
  • #3


tiny-tim said:
Hi rhettfraser! Welcome to PF! :smile:

Hint: work done = ∫ force"dot"distance = ∫ electric-field"dot"charge, and the electron will stop when the KE is zero. :wink:

thanks
 
  • #4


tiny-tim said:
Hi rhettfraser! Welcome to PF! :smile:

Hint: work done = ∫ force"dot"distance = ∫ electric-field"dot"charge, and the electron will stop when the KE is zero. :wink:

but how do you find the force?
 
  • #5
uhh? you don't, you use ∫ electric-field"dot"charge :smile:
 
  • #6
tiny-tim said:
uhh? you don't, you use ∫ electric-field"dot"charge :smile:

ok now I've worked out that the work done is 3.04x10-17
how should i work out that when KE is zero the electron will stop?
I know that W= Change in PE, is there anyway that W is related to KE?
 
  • #7
Conservation of energy … KE + PE = constant :smile:

(or work-energy theorem …KE + W = constant)
 

FAQ: Calculating Electron Trajectory in an Electric Field

What is an electric field?

An electric field is a physical field that surrounds an electrically charged particle or object. It is created by the presence of an electric charge and exerts a force on other charged particles within its vicinity.

How is the strength of an electric field measured?

The strength of an electric field is measured in units of volts per meter (V/m). This value represents the force exerted on a unit test charge placed within the field.

What factors affect the strength of an electric field?

The strength of an electric field is affected by the magnitude of the electric charge creating the field and the distance from the charge. The field strength decreases with distance from the source charge.

How is the direction of an electric field determined?

The direction of an electric field is determined by the direction of the force that a positive test charge would experience if placed within the field. The field lines point away from positive charges and towards negative charges.

What are some real-life applications of electric fields?

Electric fields have a wide range of applications in everyday life, including powering electronic devices, controlling the motion of charged particles in particle accelerators, and creating lightning in thunderstorms. They are also used in medical procedures, such as electrocardiograms and magnetic resonance imaging (MRI).

Similar threads

Find the electric field between 2 finite discs
Replies
16
Views
548
Confused about direction of electric field
Replies
7
Views
2K
Electric field in a rotating rod in a magnetic field
Replies
3
Views
1K
Electric and Magnetic field acting on an electron
Replies
25
Views
4K
Do electrons flow through a battery or is it something else?
2
Replies
44
Views
3K
I Thought I Understood Gauss' Law (Sheets)
Replies
26
Views
1K
How an Electric Field is affected by an Insulator
Replies
2
Views
2K
Accelerated Electron and its Potential Energy
Replies
5
Views
2K
Electric Field between two flat metal plates
Replies
6
Views
3K
Uncharged capacitors connected in series
Replies
18
Views
2K

Hot Threads

Recent Insights

Back
Top