Imissed a class and got this assignment yet i do not understand anything. can someone me explain ?

Two friends are having a conversation. anna says a satellite in orbit is in freefall because the satellite keeps falling toward earth. tom says a satellite in orbit is not in freefall because the acceleration due to gravity is not 9.80 m/2 . who do you agree with and why?

Steelhead trout migrate up stream to spawn. occasionally they need to leap up small waterfalls to continue their journey. fortunately, steelhead are remarkable jumpers, capable of leaving the water at a speed of 8.0 m/s. a. what is the maximum height a steelhead trout can jump? b. leaving the water at 8.0 m/s, the trout lands on top of the water fall 1.8 m high. how long was it in the air?

What is the single most important equation in all of physics?