|
172. Problem 21.49 (RHK) If the kinetic energy K and the momentum p of a particle can be measured, it should be possible to find its mass m and thus identify the particle. (a) We have to show that
(b) We have to find the limit of this expression as
|
We
have to find the mass of a particle whose kinetic energy is 55.0 MeV and
whose momentum is
and we
have to express our answer in terms of mass
of the electron.|
Solution: Click For PDF Version We know that for a particle of mass m and momentum p its energy, E, is given by
The kinetic energy K is by definition
We thus have
From this equation we get
(b) For obtaining the
We use the results that in the
(c) The mass of the particle, whose kinetic energy,
As
|
of the
above expression, we will rewrite this expression as
, 
,and whose momentum,
,will
therefore be
