A particle of mass 10 g moves along a circle of
radius 6.4 cm with a constant tangential
acceleration. What is the magnitude of this
acceleration if the kinetic energy of the particle
becomes equal to 8 × ``10^{-4}`` J by the end of the
second revolution after the beginning of the
motion?
(1) 0.1 ``\frac {m}{s^2}``(2) 0.15 ``\frac {m}{s^2}``
(3) 0.18 ``\frac {m}{s^2}`` (4) 0.2 ``\frac {m}{s^2}``