Question

The wavelength of a particular electron in motion is 35.7 nm. Given that the mass of the electron is 9.10938 x 10^-28g, calculate the velocity.

Answer 1

   = h/mv

    m       = 9.10938 x 10^-28g

   = 35.7nm = 35.7*10^-7 cm

     h           = 6.625*10^-27 erg-sec

      = h/mv

   35.7*10^-7 = 6.625*10^-27/9.10938 x 10^-28 * V

          v      = 6.625*10^-27/9.10938 x 10^-28 * 35.7*10^-7

                  = 6.625/9.10938 *35.7*10^-8

                   = 2.03*10⁶ cm/sec