9. i) WD = qV or Fd.ii) The work done gives increase in ke iii) In the direction of electric field the potential drops. Potential difference can be calc by WD/q or Ed .The electron has the same charge , hence the WD is the same but the energy exchange is from KE to EPE. Hence the initial KE = WD . The velocity can be calc by equating 0.5 mv2 = WD. The velocity should be much larger as the mass is smaller than a proton but the ke is the same as ii)
10. Use F = kQq/r2 and b) WD = EPE = kQq/r. c) The U nucleus alone has E field , hence E = kQ/r2.
