Force of an electron with magnetic and electric fields and velocity

In summary: X <-.2 k> = -1.6*10-19*<-.2, 0, 0> = <0, 3.2*10-20, 0>.This is not to be mistaken for the force, which is qE + q.v X B, which you got correct, just the cross product.
  • #1
shadowtracker
3
0

Homework Statement


An electron travels with v= 5.90(10)^{6} i through a point in space where E=<2.30 (10)^{5} i, -2.30(10)^{5} j> and B = <-0.200 k>


Homework Equations


F=q(E+(v x B)


The Attempt at a Solution


I did q of the electron equals 1.6(10)^-19 the with v x B = -.2k (5.9)10^6 i= -1.18(10)^6 j getting 1.6(10)^-19<2.3(10)^5 i, -2.3(10)^5 j + -1.18(10)^6 j> = <3.68(10)^-13 i , -1.41(10)^-13>
 
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  • #2
shadowtracker said:

Homework Statement


An electron travels with v= 5.90(10)^{6} i through a point in space where E=<2.30 (10)^{5} i, -2.30(10)^{5} j> and B = <-0.200 k>

Homework Equations


F=q(E+(v x B)

The Attempt at a Solution


I did q of the electron equals 1.6(10)^-19 the with v x B = -.2k (5.9)10^6 i= -1.18(10)^6 j getting 1.6(10)^-19<2.3(10)^5 i, -2.3(10)^5 j + -1.18(10)^6 j> = <3.68(10)^-13 i , -1.41(10)^-13>

Looks like it's OK.

I would prefer for clarity and of course the opportunity to minimize future problems to have expressed your X product a little more rigorously.

More like <5.9*106 i> X <-.2 k> = <-1.18*106 j> just to keep track of where things came from.
 
  • #3
Alright i will take that into account on future questions...and i guess i should have clarified that masteringphysics.com said i was incorrect and that the correct answer was <-3.68E-14, -1.52E-13> so I'm wondering what they did to get there.
 
  • #4
shadowtracker said:
Alright i will take that into account on future questions...and i guess i should have clarified that masteringphysics.com said i was incorrect and that the correct answer was <-3.68E-14, -1.52E-13> so I'm wondering what they did to get there.

Sorry, I scanned it and didn't calculate it out. I thought the X product was OK. But I had the axes reversed when I did the right hand rule.
I think on closer inspection it's <i> X <-k> = <+j>, not <-j>.

So try ...
-1.6*10-19*(2.3*105 i, (11.8 - 2.3)*105 j)
 

1. What is the force experienced by an electron in the presence of magnetic and electric fields?

The force experienced by an electron in the presence of both magnetic and electric fields is known as the Lorentz force. It is given by the equation F = q(E + v x B), where q is the charge of the electron, E is the electric field, v is the velocity of the electron, and B is the magnetic field.

2. How does the velocity of an electron affect the force it experiences in a magnetic field?

The velocity of an electron plays a crucial role in determining the force it experiences in a magnetic field. The force is directly proportional to the cross product of the velocity and the magnetic field. This means that the greater the velocity of the electron, the greater the force it experiences in the magnetic field.

3. What factors determine the direction of the force on an electron in a magnetic field?

The direction of the force on an electron in a magnetic field is determined by two factors: the direction of the magnetic field and the direction of the electron's velocity. The force will always act perpendicular to both the magnetic field and the velocity of the electron.

4. What is the relationship between the force on an electron and its charge in a magnetic field?

The force experienced by an electron in a magnetic field is directly proportional to its charge. This means that the greater the charge of the electron, the greater the force it will experience in the magnetic field.

5. How do electric and magnetic fields interact to affect the force on an electron?

Electric and magnetic fields interact to create the Lorentz force on an electron. This force is a combination of the electric force, which is proportional to the electric field, and the magnetic force, which is proportional to the cross product of the velocity and magnetic field. The direction and magnitude of the Lorentz force can be controlled by varying the strength and orientation of both the electric and magnetic fields.

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