Question

一物體從斜面頂端由靜止開始勻加速下滑，經(jīng)過斜面中點(diǎn)時(shí)速度為2 m/s，則物體到達(dá)斜面底端時(shí)的速度為

A.3 m/s                                                  B.4 m/s

C.6 m/s                                                  D.2 m/s

Answer 1

解析：由推論v_t²-v₀²=2as得

v₁²=2as  v₂²=2a×2s

則v₂²=2a×2s=2v₁²

v₂=v₁=2 m/s.

答案：D