# 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 $8 \times 10^{–4} J$ by the end of the second revolution after the beginning of the motion ?
( A ) $0.15 \;m/s^2$
( B ) $0.18 \;m/s^2$
( C ) $0.2 \;m/s^2$
( D ) $0.1 \;m/s^2$