A.张明做功多 |
B.李彬做功多 |
C.两人做功一样多 |
D.条件不足,无法比较做功多少 |
A.IB/△S | B.IB△S | C.B△S/I | D.I△S/B |
A.下落时A、B都克服绳的拉力做了功 |
B.下落时重力对小球A、B所做的功不相等 |
C.在最低点时vA<vB |
D.在最低点时vA>vB |
A.Wb=kWa,Ib=kIa | B.Wb=k2Wa,Ib=kIa |
C.Wb=kWa,Ib=k2Ia | D.Wb=k2Wa,Ib=k2Ia |
© 2017-2019 超级试练试题库,All Rights Reserved.