You throw a stone vertically upward with an initial speed of 6.3from a third-story office window.
1. If the window is 10above the ground, find the time the stone is in flight.
2. Find the speed of the stone just before it hits the ground.
谁帮我做一下这道题啊，因为我没有完全读懂，所以没有做对，教教我啊
