Electricity and Magnetism >
Electrostatics > Induced Charge
DCS# 5A40.30
ROTATING 2" x 4"
APPARATUS
long 2" x 4"
202-18-B
big
convex lens
202-18-B
rabbit fur
202-18-D3
styrofoam block
202-18-D6
DESCRIPTION
A 2"x4" is balanced, metal plate side
down, on a convex lens so that it can rotate freely. The
styrofoam block is
charged by rubbing it with rabbit fur. The attractive force
between the charged styrofoam and the neutral 2"x4" is large enough to
swing the 2"x4"
in a horizontal plane.
NOTES
Big convex lens would be hard to
replace. Handle with care.