Electron shot between plates (electric field)

In summary, a uniform upward electric field with a magnitude of 2.00 x 10^3 N/C has been set up between two horizontal plates, causing an electron to be shot between them at an initial velocity of 6.00 x 10^6 m/s and an angle of 45.0 degrees. The task is to determine if the electron will hit one of the plates and if so, which one and how far from the edge. To solve this, one must find the force exerted on the electron by the given electric field and then use projectile motion equations to find the horizontal and vertical components of the initial velocity and determine the electron's path.
  • #1
miroku2192
3
0

Homework Statement



I've been staring at this last problem for a while now...but i really don't get it. So if someone could explain to me how to do this, that'd be great. Thanks:

In Fig. 22-64, a uniform upward electric field E of magnitude 2.00 x 10^3 N/C has been set up between two horizontal plates by charging the lower plate positively and the upper plate negatively. The plates have length L = 10.0 cm and separation d - 2.00 cm. An electron is then shot between the plates from the left edge of the lower plate. The initial velocity of V(sub zero) of the electron makes an angle theta =45.0 degrees with the lower plate and has a magnitude of 6.00 x 10^6 m/s.
(a) will the electron strike one of the plates? (b) If so, which plate and how far horizontally from the left edge will the electron strike?

I'm really confused on this...so if someone could help that'd be great. I was never really good at physics.

Homework Equations



Relevant equations? There were none provided..?

The Attempt at a Solution



Can someone just point me in the right direction first? I'm a bit confused on how I'm supposed to go about even TACKLING the problem. Would i use the E= kQ/r^2 ? Since it's only one electron being acted on by the electric field? So it's like a point electric field thing?
 
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  • #2
miroku2192 said:
Would i use the E= kQ/r^2 ? Since it's only one electron being acted on by the electric field? So it's like a point electric field thing?
No, that's the field produced by a point charge. You already know the field. You must find the force that the given field exerts on the electron. (What's the relationship between F, E, and q?)
 
  • #3
Doc Al said:
No, that's the field produced by a point charge. You already know the field. You must find the force that the given field exerts on the electron. (What's the relationship between F, E, and q?)

Ohh...i see, so it's like a mix of electricity + projectile motions right? Because... F= Eq, and E is given, and q i know because it's the same for both protons + electrons right? something like -1.6 x 10^-19? Anyway, after i find the force in Newtons, i can just set it up as F = mass x acceleration, figure out acceleration and use projectile motions stuff right? I'm a bit shakey on projectile motions stuff though...when it says "a magnitude of 6.00 x 10^6 m/s.", does that mean after i find out acceleration, the initial velocity value i use is 6.00 x 10^6 m/s ?
 
  • #4
miroku2192 said:
Ohh...i see, so it's like a mix of electricity + projectile motions right? Because... F= Eq, and E is given, and q i know because it's the same for both protons + electrons right? something like -1.6 x 10^-19? Anyway, after i find the force in Newtons, i can just set it up as F = mass x acceleration, figure out acceleration and use projectile motions stuff right?
Exactly right.
I'm a bit shakey on projectile motions stuff though...when it says "a magnitude of 6.00 x 10^6 m/s.", does that mean after i find out acceleration, the initial velocity value i use is 6.00 x 10^6 m/s ?
Yes, but realize that the initial velocity is at an angle, so you need to find horizontal and vertical components. Only the vertical component of motion is accelerated--just like with regular projectile motion.
 
  • #5
Doc Al said:
Exactly right.

Yes, but realize that the initial velocity is at an angle, so you need to find horizontal and vertical components. Only the vertical component of motion is accelerated--just like with regular projectile motion.

Oh right...i have to split up the x components and y components...Thanks so much, i think i get this question now. I really appreciate ALL your help!
 

1. What is an electric field?

An electric field is a region around a charged particle or object where a force is exerted on other charged particles or objects.

2. How is an electric field created between two plates?

An electric field is created between two plates when one plate has a positive charge and the other has a negative charge. This creates a potential difference between the plates, resulting in an electric field.

3. How does an electron behave when shot between the plates?

When an electron is shot between the plates, it will experience a force from the electric field. Depending on its initial velocity and the strength of the electric field, the electron may be accelerated or decelerated as it moves between the plates.

4. What factors affect the motion of an electron in an electric field?

The motion of an electron in an electric field is affected by its initial velocity, the strength of the electric field, and the distance between the plates. The mass and charge of the electron also play a role in its motion.

5. What are some practical applications of studying electrons in an electric field?

Studying electrons in an electric field can help us understand and develop technologies such as particle accelerators, cathode ray tubes, and electronic devices like televisions and computer screens. It also has applications in fields such as physics, engineering, and telecommunications.

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