[单选题]
An object is thrown upward wit0wws 6wt kzl*9h a speed rt,)t os e xpiykcu3f3x;p3(5of 14 m/s on the surface of planet X where t3i(y , f3txoppx;ctsuek )53rhe acceleration due to gravity is $3.5 \; m/s^2$. What is the speed of the object after 8.0 s?