1.What is a reference system? 2.What is path, road and move? 3.What is speed? 4. How is acceleration defined? 5.What is a rigid body?
6. What is the angular displacement and the described angle?
7.Angular velocity. Angular acceleration. Period and frequency.

(sorry, i had to translate these on google because idk how to translate some terms, if you know serbian, i can send you on serbian)

1. reference system - a system that uses coordinates to establish position coordinate system , frame of reference , reference frame organization , arrangement , organisation , system - an organized structure for arranging or classifying; "he changed the arrangement of the topics"; "the facts were familiar but it was in the organization of them that he was original"; "he tried to understand their system of classification"

2. Path- a way or track laid down for walking or made by continual treading. Road- a wide way leading from one place to another, especially one with a specially prepared surface which vehicles can use. Move- go in a specified direction or manner; change position.

Explanation:

b.a device that inputs heat into a cool object