ToughSTEM
Sign Up
Log In
ToughSTEM
A question answer community on a mission
to share Solutions for all STEM major Problems.
Cant find a problem on ToughSTEM?
0
A simple and common technique for accelerating electrons is shown in the figure, where there is a uniform electric field between two plates. Electrons are released, usually from a hot filament, near the negative plate, and there is a small hole in the positive plate that allows the electrons to pass through.
Calculate the horizontal component of the acceleration of the electron if the field strength is 2.55*10^4 N/C. Express your answer in m/s^2 and assume the electric field is pointing in the negative x-direction.
Edit
Added Wed, 08 Jul '15
Community
1
Comment
Add a Comment
Solutions
0
1. The direction of motion of the electron

2. Horizontal component.

There is a rule of thumb that you may come across several times while solving physics problems; it is that a negetive particle will always ravel or accelarte in the direction opposite to that of the electric field and a positive particle in the direction of the field. Now, since elcetron is a negetively charged particle, it travels in a direction opposite to the direction of the field.

If there is a horiontal component, there will be a vertical component too. Here the vertical component is gravitation accelaration (assuming that we are carrying this experiment on Earth :P ) . The question only concerns the horizontal component which means that the accelaration caused by the electric field on the electron.

Now, we move to the question. a= f/m where f= force on the paticle and m= mass of the particle. Now we know that mass of electron is 9.10938291 * 10^-31 kilograms i.e m=9.10938291 * 10^-31 kilograms. We now need to determine the value of force acting on the particle.

Force f on a particle is the product of the charge q and electric field E acting on the particle. i.e f=q*E. The value of q= -1.60217657 * 10-19 C and E= -2.55*10^4 N/C(as the electric field points towards the negative x direction).

Hence the value of f becomes q*E which is -1.60217657 * 10-19 *(- 2.55*10^4) =4.0855*10^-15 N.

The positive sign suggests that the force acting on the electron is in the direction opposite to the direction of the electric field and hence towards the positive x axis. So , the value of accelaration a(horizontal component) will be.

a=f/m =4.0855* 10^-15 N/ (9.10938291 * 10^-31)= 4.485 * 10^15 m/s^2

The acceleration remains constant between the plates because the electric field is uniform.
Edit
Added Wed, 08 Jul '15
Community
1
Comment
Add a Comment
Add Your Solution!
Close

Click here to
Choose An Image
or
Get image from URL
GO
Close
Back
Add Image
Close
What URL would you like to link?
GO
α
β
γ
δ
ϵ
ε
η
ϑ
λ
μ
π
ρ
σ
τ
φ
ψ
ω
Γ
Δ
Θ
Λ
Π
Σ
Φ
Ω
Copied to Clipboard

Add Your Solution
Sign Up
to interact with the community. (That's part of how we ensure only good content gets on ToughSTEM)
OR
OR
ToughSTEM is completely free, and its staying that way. Students pay way too much already.
Almost done!
Please check your email to finish creating your account!
Welcome to the Club!
Choose a new Display Name
Only letters, numbers, spaces, dashes, and underscores, are allowed. Can not be blank.
Great! You're all set, .
A question answer community on a mission
to share Solutions for all STEM major Problems.
Why
The Purpose
How
The Community
Give Feedback
Tell us suggestions, ideas, and any bugs you find. Help make ToughSTEM even better.