Convection, conduction, and radiation.
Basically, the temperature is a result of the average kinetic energy of all the atoms comprising the solid/liquid/gas. In solid, these atoms can just vibrate in place, leaving them to only be able to conduct and radiate heat. However, as you probably know liquids and solids take the shape of their container because the bonds between atoms are loose enough to allow them to freely move around. Due to each individual atom having its own energy, and these atoms being free to move about the liquid/gas they collide with other atoms in the substance. These collisions result in a transfer of energy. Finally, lower energy atoms "sink" and higher energy atoms "rise" thus creating a "convection current".
Answer:
r = √ x² + y² and θ = tan⁻¹ y / x
Explanation:
The polar coordinates are obtained by transforming the Cartesian coordinates (x y) into others (r tés), for this we use to find r the Pythagorean theorem
r = √ x² + y²
To find teas we use trigonometries
tan θ = y / x
θ = tan⁻¹ y / x
In general the angle can be given in any unit, but the most used in physics is in radians
