Gravitational Force Grade 5

Hi 5th graders!!
How do you do?
I have a video that can help you to learn about gravitational force.
Can you open this link?

https://www.youtube.com/watch?v=ljRlB6TuMOU

Now, please answer this questions. Write down the answer on your e-mail and send it to my e-mail.
Here are the questions:
1. Who is the first person who studied about gravity?
2. How can he find out that there is gravitional force of the earth?
3. When you throw a ball upwards, where will it go? Why?

That's all. I'll wait for your answers in my e-mail.