Calculating distance of an electron moving between 2 plates

  • Thread starter Thread starter Combine
  • Start date Start date
  • Tags Tags
    Electron Plates
AI Thread Summary
Electrons accelerated by a 1,000-volt potential difference are analyzed as they move between two parallel plates, measuring 0.15m in length and 0.030m apart, with an electric field of 2,000 N/C. The acceleration of the electrons is calculated to be 3.52 x 10^14 m/s², leading to a final velocity of approximately 1.9 x 10^7 m/s before entering the plates. The time taken to traverse the length of the plates is found to be 7.0 x 10^-9 seconds. Using the equations of motion, the vertical deflection of the electrons is determined to be 0.008624m, which aligns with expectations given the dimensions of the setup. The calculations are confirmed to be logical and consistent with the physical scenario presented.
Combine
Messages
14
Reaction score
0

Homework Statement


Electrons are accelerated from REST by a potential difference of 1.0 x 10^3 volts
They pass midway between two flat parallel plates 0.15m long and 0.030m apart. The electric field between the plates has a magnitude of 2.0 x 10^3 N/C. Determine how far an electron will be deflected (x) from it's original horizontal path by the time that it reaches the other end of the plates

I can't use most of the formulas because there is constant acceleration involved after it reaches the 0.35 m mark, thus I can't get a x nor a y and the acceleration is just in the X axis,
I'm really stuck!

can anybody please help me?

Homework Equations


e = 1.602 x 10^-19
m = 9.11 x 10^-11
k = 9.0 x 10^9 N M^2/C^2

ε = V/r
ε = Fe/q
Vf^2 = Vi^2 + 2ad
d = v2t - 1/2at^2
d = v1t - 1/2at^2

The Attempt at a Solution


First find the acceleration
F = ma
qε = ma
(1.602x10^-19)(2000) = 9.11 x 10^-31a
a = 3.52 x 10^14

next find the distance between starting position and the end of the plates
ε = V/r
2000 = 1000/r
r = 0.50

after that find the distance between starting position and the start of the plates
0.50 - 0.15 = 0.35m

next you find the final velocity (the second before the electron reach's the plates)
Vf^2 = Vi^2 + 2(3.52x10^24)(0.35)
vf = 1.6 x 10^7
 

Attachments

  • Untitled.jpg
    Untitled.jpg
    6.2 KB · Views: 490
Last edited:
Physics news on Phys.org
The first thing to do is calculate the velocity of electrons accelerated through 1000V
use eV = 0.5mv^2
These electrons then travel into the space betwen the parallel plates where they experience a vertical force.
Hope this helps
 
Well it only kinda helped, I am still unsure if that is the answer.

eV = 1/2mv^2
1.602 x 10^-16 = 4.555 x x10^-31V^2

v = 1.9 x 10^7

t = 0.15/1.9 x 10^7
t = 7.0 x 10^-9

d = V1t + 1/2at^2
d = 0 + 1/2(3.52 x 10^14)(7.0 x 10^-9)
d = 0.008624

The answer makes logical sense, because we know that the space between the plates is 0.030m

and it's only deflected a bit so it would make sense that the vertical deflection would be 0.008624m

can anyone confirm this?
 
TL;DR Summary: I came across this question from a Sri Lankan A-level textbook. Question - An ice cube with a length of 10 cm is immersed in water at 0 °C. An observer observes the ice cube from the water, and it seems to be 7.75 cm long. If the refractive index of water is 4/3, find the height of the ice cube immersed in the water. I could not understand how the apparent height of the ice cube in the water depends on the height of the ice cube immersed in the water. Does anyone have an...
Thread 'Variable mass system : water sprayed into a moving container'
Starting with the mass considerations #m(t)# is mass of water #M_{c}# mass of container and #M(t)# mass of total system $$M(t) = M_{C} + m(t)$$ $$\Rightarrow \frac{dM(t)}{dt} = \frac{dm(t)}{dt}$$ $$P_i = Mv + u \, dm$$ $$P_f = (M + dm)(v + dv)$$ $$\Delta P = M \, dv + (v - u) \, dm$$ $$F = \frac{dP}{dt} = M \frac{dv}{dt} + (v - u) \frac{dm}{dt}$$ $$F = u \frac{dm}{dt} = \rho A u^2$$ from conservation of momentum , the cannon recoils with the same force which it applies. $$\quad \frac{dm}{dt}...
Back
Top