A pelican flying along a horizontal path drops a fish from a height of 4 m. The fish travels 8.0 m horizontally before it hits the water below. What is the pelican’s speed

The substances that are necessary for producing of certain hormones and that store and transport vitamins

22. the top of a cliff is located a distance h above the ground. at a distance h/2 there is a branch that juts out from the side of the cliff, and on this branch a bird's nest is located. two children throw stones at the nest with the same initial speed, one stone straight downward from the top of the cliff and the other stone straight upward from the ground. in the absence of air resistance, which stone hits the nest in the least amount of time?

Ineed to answer this problem but i lack in knowledge, what should i study to answer this problem? i have never used derivatives in a physics problem so i'm not sure what's happening and i can't find videos explaining.