• Support PF! Buy your school textbooks, materials and every day products Here!

Kinetic Energy of Protons

Homework Statement
Hi! So for my a levels I’ve been doing practice papers and I’m stuck. I have to calculate the kinetic energy of a proton after acceleration except I’m only given the charge of +1.6x10^-19 , a potential difference of 80kV, and a mass of 1.7x10^-27kg
Homework Equations
Kinetic energy = 1/2 x mass x velocity^2
So first I tried to use KE=1/2 x m x v^2 but then realised I didn’t have the velocity and I can’t figure out a way to obtain it. I then tried to work out the energy using a different equation, W= q x v but that left me with 1.28x10^-14 J which seemed too small.

I also then have to calculate the maximum speed of the proton which I’m confused at how to do if I don’t have the velocity.

Thanks in advance!
 

Orodruin

Staff Emeritus
Science Advisor
Homework Helper
Insights Author
Gold Member
2018 Award
16,081
6,021
You have the charge and you have the change in electric potential. What does this mean for the change in the potential energy of the proton and where does this potential energy go during acceleration?
 
Oh so do I use V= p.e. / q because the electrical energy has been transferred to kinetic energy during the acceleration?
 

Orodruin

Staff Emeritus
Science Advisor
Homework Helper
Insights Author
Gold Member
2018 Award
16,081
6,021
That does seem like a viable option, yes.
 
Thank you for your help!
 

PeroK

Science Advisor
Homework Helper
Insights Author
Gold Member
2018 Award
10,335
3,932
Thank you for your help!
Note that the joule is the SI unit of energy. In particle physics, however, it's more usual to use the electron-volt as the unit of energy. This is the energy gained by an electron ( or other particle with the same charge) accelerated through 1 volt.

Another way to do your problem is to use the immediate answer in terms of electron volts and then look up the conversion to joules.
 

Want to reply to this thread?

"Kinetic Energy of Protons" You must log in or register to reply here.

Related Threads for: Kinetic Energy of Protons

  • Last Post
Replies
1
Views
21K
  • Last Post
Replies
1
Views
13K
  • Last Post
Replies
7
Views
71K
Replies
2
Views
15K
Replies
3
Views
966
Replies
1
Views
1K
Replies
2
Views
6K
  • Last Post
Replies
2
Views
2K
Top