Question

Lets say that you are a physics student and you were assigned the task of Determining the electrostatic constant k using the equipment given below.

Please explain how you would utilize the materials provided to accomplish this goal.

(1) Van de Graaff generator
(2) Two silver balls (4 mm diameter)
(3) Four rubber stops
(4) One tube of adhesive
(5) Lab jacks (various sizes from 1 cm x 1 cm to 10 cm x 10 cm)
(6) Wooden board (1 cm x 40 cm x 60 cm)
(7) Wooden board (1 cm x 60 cm x 80 cm)
(8) Four wooden rods (0.5 cm diameter, 50 cm length)
(9) Roll of white paper (1 meter width)
(10) Scissors
(11) DC Power supply (any voltage)
(12) Insulated tweezers
(13) One jar of black ink
(14) Package of small water color paint brushes (various sizes)
(16) Two copper plates (50 cm x 50 cm)
(17) Roll of kite string
(18) Box of thumb tacks
(19) Tube of superglue
(20) Rulers of various lengths (can be used to measure distances in cm)

Hint: The Van de Graaff generator can be used to deposit a measurable charge on either
of the silver balls. The copper plates can be arranged vertically and separated accurately
by arbitrary distances.
Pioneer: Charles?Augustin de Coulomb discovered Coulomb’s Law.

Answer 1

SOLUTION

According to Coulomb's Law:

Isolating the electrostatic constant   from equation (1) we have:

The charges and are the same, so:

Now, the value of charge can be obtained with the van der graaf generator. The voltage applied is proportional to charge received by spheres.