# A body of mass $m = 10^{-2} kg$ is moving in a medium and experiences a frictional force $F= -kv^2$. Its initial speed is $v_0 = 10\; ms^{-1}$. If after 10 s, its energy is $\frac{1}{8} mv_0^2$, the value of $k$ will be :
( A ) $10^{-3} Kg \; s^{-1}$
( B ) $10^{-4} Kg \; m^{-1}$
( C ) $10^{-3} Kg \; m^{-1}$
( D ) $10^{-1} Kg \; m^{-1}s^{-1}$