2. Ten bricks, each 10 cm thick and mass 1 kg, lie on a flat floor. How much work is required to stack them on top of one another? Assume the bricks have uniform density.
(A) 40 J,
(B) 44.1 J,
(C) 49.5 J,
(D) 55 J.
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統計: 尚無統計資料
統計: 尚無統計資料