A small sphere of mass, m “ 250.0 g, carries a charge of q “ ´450.0 µC. It’s tied
to a massless string of length, L “ 8.00 cm, which is tied to a horizontal post at point, P.
There are two very large horizontal plates at y “ ˘12.0 cm. The top plate carries a charge of
σT “ `7.65 pC{cm2
, and the bottom plate carries a charge of σB “ ´7.65 pC{cm2
. The string
is initially stretched and held at an angle of θ0 “ 94.0
˝ with the positive x-axis.

Find:
a) Where will the sphere be 1.25 seconds after it is let go?
b) What is the sphere’s velocity at this instant?
c) If the string breaks at this instant, which plate will the sphere first hit?
d) Where will it hit the plate? (Give the x-coordinate.)
e) What will its velocity be at the instant it hits the plate?