A brass wire is 1.40 m long and has a cross-sectional area
of 6.00 mm2. A small steel ball with mass 0.0800 kg is attached to the
end of the wire. You hold the other end of the wire and whirl the ball in
a vertical circle of radius 1.40 m. What speed must the ball have at the
lowest point of its path if its fractional change in length of the brass wire
at this point from its unstretched length is 2.0 * 10-5? Treat the ball as
a point mass.