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在排球比赛中,被击回的球,无论触网而不过还是越界都会失分。现在我们用学过的平抛运动知识,来分析排球击球不触网且不越界的条件。例1．如图所示,排球场总长为18m,设网高H为2m,运动员站在离网3m线上正对网前跳起高度h为2.5m处将球水平击出,试问球的初速度在什么范围内,才能使球既不触网也不越界?(g取10m/s~2)
In a volleyball game, a ball that is hit back will lose points whether it touches the net or crosses the border. Now we use the knowledge of flat throwing sports that we have learned to analyze the conditions under which volleyball hits the ball without touching the net and not crossing the border. example 1. As shown in the figure, the total length of the volleyball court is 18m, and the net height H is set to 2m. The athlete stands on the 3m off-net line and is facing the height of the net and h is 2.5m. The ball is hit horizontally. The initial speed of the ball is In what scope can the ball be neither touched nor crossed? (g takes 10m/s~2)