题目

求解一道AP微积分应用题!
A ball is thrown upward from the top of a building feet tall.The height of the ball is described by the function y(t),=-16t^2+14t+250.where t is in seconds and t=0 corresponds to the moment the ball is thrown.
(1)Determine for which value of t the ball reaches the maximum height and determine this maximum height.
(2)
Determine when the ball reaches the ground.
(3)With what velocity does the ball hit the ground?

提问时间：2021-04-01

答案

（1）第一问求t为何值时球达到最大高度 y'(t)=-32t+14 令其等于0 解得t=7/16 再带入 y(t),=-16t^2+14t+250 解得最大高度（2）第二问球什么时候落地令y(t),=-16t^2+14t+250=0 解得的t（取正的那个）就是（3）问球落地...