两种情况下子弹损失的动能分别是:△E1= 1 2 m v ? 1 2 m(0.8v0)2=0.36? 1 2 m v △E2= 1 2 m(0.8v0)2? 1 2 m(0.6v0)2=0.28? 1 2 m v 根据动能定理:△E=W所以: W1 W2 = △E1 △E2 = 0.36 0.28 =9:7又:W=FS所以: S1 S2 = W1 W2 = 9 7 故选:B