  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
In an electron microscope, there is an electron gun that contains two charged metallic plates 2.90 cm apart. An electric force accelerates each electron in the beam from rest to 9.20% of the speed of light over this distance. (Ignore the effects of relativity in your calculations.)
(a) Determine the kinetic energy of the electron as it leaves the electron gun. Electrons carry this energy to a phosphorescent viewing screen where the microscope's image is formed, making it glow.
(..........) J

(b) For an electron passing between the plates in the electron gun, determine the magnitude of the constant electric force acting on the electron.
(...........) N

(c) Determine the acceleration of the electron.
(..........) m/s2

(d) Determine the time interval the electron spends between the plates.
(..........) s  Edit
Added Tue, 21 Jul '15 Community
1
Comment  Add a Comment
Solutions
0

Initial speed = 0

Final speed = (9.2/100) * 3 * 10^8 = 0.276 * 10^8 m/s

a) KE = 0.5 * m * v^2 = 3.46 * 10^-16 J

b) Change in KE = work done
Initial KE = 0 as inital velocity = 0 and final KE = 3.46 * 10-^16 J
So, 3.46 * 10^-16 J = work done = Force * distance
3.46 * 10^-16 J = Force * 2.90 * 10^-2 m
Hence, force = 1.19 * 10^-14 N

c) Acceleration = force / mass =  1.19 * 10^-14 N / 9.1 * 10^-31 = 1.3 * 10^16 m/s^2

d) Final speed = Inital speed + acceleration * time

Hence, T = 0.276 * 10^8 m/s / 1.3 * 10^16 m/s^2 = 2.076 * 10^-9 seconds  Edit
Added Tue, 21 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.