Electron beam is accelerated from rest through pd 5000 V and impinge normally onto the wall of building with an incident current 25$\mu$A. What force is exerted on wall?

Question

anonymous · Answer

final kinetic energy of electron= charge * pd = e*V= 5000e
final momentum=sqrt(2m * 5000e) 
in time t , the total loss of momentum =m*v*I*t/e
force = rate of change of momentum=d/dt  (m*v*I*t/e) = mvI/e
      = sqrt(2m * 5000e)  * I/e
use |dw:1340275728230:dw|