Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Super Cool Problem

  1. Sep 26, 2005 #1
    Milliken Oil Drop Problem anyone??? Help please.

    Can some one help me with this Milliken oil drop problem.

    Data from a Milliken oil drop experiment are given below. Calculate the value of the charge on an electron from this data:

    Voltage needed to suspend drop (V) Drop diameter (microns)
    103------ 1.1
    44.7----- 1.2
    127------ 1.6
    175------ 1.5
    11.3----- 0.9

    Plate separation: 0.5cm
    Density of oil: 0.95 g/mL
    Gravitational constant: 9.80 m/s^2

    Ok... this is what I did: q=mg/E
    1. I calculated for electric field first since: E= kV/m
    2. One microns is equal to 10^-6 m
    3. I changed volts into kV.
    4. I took the average of all 5 of the electric fields and got 67896.71718 kV/m
    5. Now I solved for the mass by cubing the plate separation and cancelled it with the mL... to get grams then I changed grams into kilograms to get 1.1875 x 10^-4 kg.
    6. And finally I plug everything back into the equation: q=mg/E and get the answer of 2.706 x 10^-8 coulombs.

    Please tell me if I did it right.
    Last edited: Sep 26, 2005
  2. jcsd
  3. Sep 26, 2005 #2
    come on anyone please help me or at least tell me if I'm in the right direction.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook