# What is the speed of the proton?

1. May 1, 2012

### yy205001

what is the speed of the proton??

1. The problem statement, all variables and given/known data
What is the speed of a proton after being accelerated from rest through a 50x106 potential difference?

m_proton = 1.67x10-27kg
C = 1.6x10-19 c
* This question is in Relativity.
2. Relevant equations
Voltage(v) = Joule(j)/Columb(c)
K = 1/2(mu2)

3. The attempt at a solution
Firstly, i timed 1.6x10-19 to 50x106 to find the Energy(j
). Then plugged into the kinetic energy formula to find u(speed_proton). But which is wrong. what is the mistake?

Last edited: May 1, 2012
2. May 1, 2012

### sweet springs

Re: what is the speed of the proton??

Hi. It seems OK to me. How did you judge you are wrong?
By the way
m_proton = 1.67x106kg is too heavy! -6?, not sure. You should check it in some physics table.

3. May 1, 2012

### yy205001

Re: what is the speed of the proton??

it should be -27. I was doing a online HW. when i typed in the answer, the system said that it was wrong.

4. May 1, 2012

### yy205001

Re: what is the speed of the proton??

Does proton carry the same charge as electron??(c=1.6x10^-19)

5. May 1, 2012

### truesearch

Re: what is the speed of the proton??

If you use KE equation you get a speed of about 1x10^8 m/s.....this is a bit too close to the speed of light and you may need to use relativity equation.

6. May 1, 2012

### tms

Re: what is the speed of the proton??

If the speed is relativistic, then that is not the correct equation for kinetic energy.