Question

Proton has a mass of 1840 times that of an electron if a proton is accelerated from rest by a pd of 1 v its kinetic energy is

Answer 1

When in motion  then we have to make the following assumptions :
the potential energy remains 0
In-order to calculate the kinetic Energy:
PE* = 0,
 KE* = 1/(2mv^2)

Now since PE +KE = Total energy =PE* + KE*

qV + 0 = 0 + 1/2mv^2 

The second formulae we can use to calculate the kinetic Energy is given by

 KE = qV 
where the charge of the proton is  1.6 x 10^-15 C  and where v is the potential difference.

Kinetic Energy is given by 
     1.6 x 10^-19C x 1v= 1.6 x10^-19 J
 Therefore, the answer is given by 1.6 x 10^-19J