A person scuffing her feet on a wool rug on a dry day accumulates a net charge of -93μC .How many excess elect?

3 Answers

• For physics problems, it’s best to start off by listing everything that’s given:

  Net charge (Q) = -93 μC

  Although not given, the following info should be known:

  mass of electron (me) = 9.1 x 10^-31 kg

  charge of electron (q) = -1.6 x 10^-19 C

  For the first question:

  The number of electrons (N) equals the total charge divided by the charge per electron:

  N = Q/q = (-93)(10^-6) / (-1.6)(10^-19)

  N = 5.8 x 10^14 electrons

  Second question:

  If the she has 5.8 x 10^14 excess electrons, then her mass increases by the mass per electron times each of the excess electrons:

  In other words:

  Increase in the mass of lady

  = N(me)

  = (5.8)(10^14)(9.1)(10^-31)

  = 5.3 x 10^-16 kg

  Hope I helped..

• Scuffing

• elementary charge = 1.60217657 × 10-13 μC

  93μC / 1.60217657 × 10-13 μC/electron = 58.05 x 10^13 electrons

  9.10938291×10−31 kg/electron * 58.05 x 10^13 electrons = 5.29 x 10^-16 kg