3.“智勇大沖關(guān)”最后一關(guān)有如圖所示的滑道,沖關(guān)者坐上坐墊從A點(diǎn)靜止開始沿傾斜直軌道AB滑下,斜道傾角θ=37°;離B點(diǎn)很近銜接一長L=2m的光滑氣墊,B與C兩點(diǎn)可認(rèn)為平滑銜接(速度大小不變),A點(diǎn)距光滑氣墊垂直距離為h=2.4m,沖關(guān)者經(jīng)C點(diǎn)到D點(diǎn)后水平拋出,落在水面上一點(diǎn)E。已知:光滑氣墊末端距水面高度H=0.8m,坐墊與AB斜道間動(dòng)摩擦因數(shù)為μ=0.5。(sin37°=0.6,cos37°=0.8)g=10m/s
2;求:
(1)沖關(guān)者到達(dá)B點(diǎn)時(shí)的速度大?。?br />(2)求沖關(guān)者沖過D點(diǎn)后的平拋水平射程;