[填空题]
At serve, a tennis player aimstv*f.(u /hpc 8de11t 1i wez5e ud5uzz,n*uc u to hit the ballq5lkh;,x+7+qk )coun5brz hu horizontally. What minimum speed is require)+5k5cbhz,knqq+7uuhx r;l od for the ball to clear the 0.90-m-high net about 15.0 m from the server if the ball is “launched” from a height of 2.50 m? $\approx$ Where will the ball land if it just clears the net (and will it be “good” in the sense that it lands within 7.0 m of the net)? How long will it be in the air? $\approx$ See Fig. below.
