American Football originated from which two sports? A) Soccer and Rugby

B) Rugby and Basketball

C) Cricket and Soccer

D) Soccer and Volleyball

In which of the following is positive work done by a person on a suitcase

2) why do satelites not fall while revolving around the earth?

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.