A.乘客以乙船為參照物,而且乙船行駛比較快 B.乘客以甲船為參照物,而且乙船行駛比較快 C.乘客以地面為參照物,而且乙船行駛比較快 D.兩船相對(duì)靜止
A.360J B.450J C.540J D.720J
A.1200W B.1800W C.3000W D.3600W