The mass of a proton is 1836 times the mass of an electron.

In summary, a proton has 1836 times the mass of an electron, and their kinetic energies are the same.
  • #1
Mdhiggenz
327
1

Homework Statement



The mass of a proton is 1836 times the mass of an electron.

A) A proton is traveling at speed . At what speed (in terms of ) would an electron have the same kinetic energy as the proton?

B) An electron has kinetic energy K . If a proton has the same speed as the electron, what is its kinetic energy (in terms of K )?

Homework Equations





The Attempt at a Solution



The answer for A is 42.85, and to get it here is what I did.

Kp-ke=0

Kp=Ke

1/2mv^2=1/2(1836m)v^2

Ve=squareroot(2*918vp)=42.85

Part B the answer is 1836

But I have no clue on how to get it. Since their velocities are equal I was thinking of setting them both to 1.

1/2m(1)^2=1/2(1836m)(1)^2

I don't know what to do after this.. tried solving for M but that doesn't make sense.

Thank you
 
Physics news on Phys.org
  • #2
Hi Mdhiggenz! :smile:

Where's the difficulty? :confused:

Just call the velocity "v", write out the KE for both particles, and find their ratio …

what do you get? :smile:
 
  • #3
Hello,

As i see from your previous posts you have a little trouble in solving equations :-)
Don't worry it will go away with practice.

Write the KE=(mv*2)/2

so v^2=2KE/m

now since velocity for proton and electron is given equal we have
2KE(p)/m(p) = 2KE(e)/m(e) (here KE(p) means kinetic energy of proton)

now you have a relation between m(p) and m(e) so equate the two equations above.
 
  • #4
I got Ke(p) = 2ke/me*mp is that correct?
 
  • #5
No, the factor of 2 is extra.
RHS should not have the factor 2.

As i have written 2KE(p)/m(p) = 2KE(e)/m(e)

i.e same as KE(p) = KE(e)/m(e) *m(p)
 
  • #6
Thx email I finally got it. I was missing the mp=1836me relation ship and when you plug and chug using the ration is all makes sense.
 

Related to The mass of a proton is 1836 times the mass of an electron.

1. How is the mass of a proton determined?

The mass of a proton is determined through experiments and calculations using various scientific instruments, such as mass spectrometers and particle accelerators.

2. What is the significance of the mass ratio between a proton and an electron?

The mass ratio between a proton and an electron, which is approximately 1836, is significant because it helps us understand the fundamental structure of atoms and the forces that hold them together.

3. Why is the mass of a proton important?

The mass of a proton is important because it is the building block of all elements and plays a crucial role in determining the properties of atoms and molecules.

4. How does the mass of a proton compare to other subatomic particles?

The mass of a proton is significantly larger than the mass of an electron, but smaller than the mass of a neutron. It falls in between these two particles in terms of mass.

5. Can the mass of a proton change?

The mass of a proton is considered to be a constant value and does not change under normal circumstances. However, it can be altered under extreme conditions such as high energy collisions or in the presence of strong magnetic fields.

Similar threads

  • Introductory Physics Homework Help
Replies
10
Views
517
  • Introductory Physics Homework Help
Replies
4
Views
1K
  • Introductory Physics Homework Help
Replies
4
Views
1K
  • Introductory Physics Homework Help
2
Replies
54
Views
8K
Replies
11
Views
1K
  • Introductory Physics Homework Help
Replies
2
Views
2K
  • Introductory Physics Homework Help
2
Replies
44
Views
834
  • Introductory Physics Homework Help
Replies
3
Views
1K
  • Introductory Physics Homework Help
Replies
14
Views
3K
  • Introductory Physics Homework Help
Replies
7
Views
2K
Back
Top