An electron with known speed and distance from a proton moving away?

In summary: The force on the electron can be found using Coulomb's Law: F = k(Qe)(Qp)/r^2, where k is the constant of proportionality, Qe is the charge of the electron, Qp is the charge of the proton, and r is the distance between them. In this case, Qe = -1.6e-19 C, Qp = 1.6e-19 C, and r = 10e-10 m. Plugging in these values and solving for F, we get F = 2.3e-8 N.Now, to explain the motion of the electron in terms of energy conservation, we can use the equation for kinetic energy, KE =
  • #1
zoomrocket88
6
0

Homework Statement


Suppose that an electron is set down 10e-10 m away from a proton that is "pinned down" so that the proton cannot move. The electron has a velocity V0= 1.6e6 m/s pointing away from the proton, along the line between the proton and the electron. What is the force on this electron? Explain its motion in terms of energy conservation. How far away will it get from the proton? Where will it end up?


Homework Equations


Not sure


The Attempt at a Solution


I am stumped at how to go about this. I know that you should turn the changing kinetic energy into potential energy, and that eventually the electron will stop and come back to the proton if the attractive force is grater than the initial velocity of the electron, but I have no idea how to go about it.
 
Physics news on Phys.org
  • #2
You need Coulomb's Law. You need the kinetic energy equation. Force and velocity are not comparable quantities.
 
  • #3
Alright so I can find the values for kinetic energy and the force from those equations, but how do I relate the two to find out how far the electron will go?

I have 1.16e-18 J and 2.30e-8 C so far...
 
  • #4
I suppose you could divide the two and get the Electric Potential but I don't think that would help...
 
  • #5
I found an equation that states that an electron will escape the pull of a proton if:
V=sqrt (2kQe/mr) but I can't tell if Qe is one value or two. Any help?
 
  • #6
Please state Coulomb's Law for us. Please give your math in "complete sentences" (use equations, not just numbers or expressions).
 
  • #7
While you're at it, also state the equation for electric potential energy.
 
  • #8
Coulomb's law states that the force of attraction or repulsion between two charged particles is directly proportional to the product of the charges and inversely proportional to the distance between them.
 
  • #9
The equation for potential energy is PE= kQq/r
 
  • #10
zoomrocket88 said:
Coulomb's law states that the force of attraction or repulsion between two charged particles is directly proportional to the product of the charges and inversely proportional to the distance between them.
Excellent. And, these days, we know the constant of proportionality, so when you look up Coulomb's law in a textbook, for instance, you will see this constant, and the textbook will tell you it's value. Use this to answer the first question (What is the force).
 

FAQ: An electron with known speed and distance from a proton moving away?

What is the force between an electron and a proton moving away from each other?

The force between an electron and a proton moving away from each other is known as the Coulomb force. It is an attractive force that follows the inverse square law, meaning that as the distance between the two particles increases, the force decreases.

How does the speed of the electron affect the distance between the electron and the proton?

The speed of the electron does not directly affect the distance between the electron and the proton. However, as the speed of the electron increases, the force between the two particles also increases, causing the distance between them to decrease.

What is the relationship between the distance from the proton and the potential energy of the electron?

The potential energy of the electron is directly proportional to the distance from the proton. As the distance increases, the potential energy also increases. This is because the force between the two particles is weaker at larger distances, resulting in a higher potential energy.

Can the electron's speed and distance from the proton change over time?

Yes, the electron's speed and distance from the proton can change over time due to various factors such as external forces or interactions with other particles. The direction and magnitude of these changes depend on the initial conditions and the forces acting on the electron.

How does the motion of the electron affect the motion of the proton?

The motion of the electron and the proton are interdependent. As the electron moves away from the proton, the proton will also move in the opposite direction due to the conservation of momentum. However, the mass difference between the two particles means that the proton's motion will be much smaller compared to the electron's motion.

Similar threads

What is the correct velocity of an electron in a bound orbit around a proton?
Replies
2
Views
1K
What Was the Initial Speed of the Proton in a Collision?
Replies
2
Views
2K
Work to move electron/proton between the plates of a charged capacitor?
Replies
22
Views
3K
De Broglie wavelength of electron and proton
Replies
14
Views
3K
An electron & a proton are each placed in an electric field
Replies
1
Views
2K
Determining speed of electron in a parallel plate capacitor
Replies
3
Views
9K
Relativistic electrons and positrons
Replies
2
Views
1K
What is the kinetic energy of a proton when neutron decays?
Replies
20
Views
5K
I The kinetic energy of proton-electron for a black body
Replies
8
Views
2K
A proton and an positron (identical to an electron, except positivel
Replies
4
Views
2K

Hot Threads

Recent Insights

Back
Top