An example of mechanical energy being converted into heat energy is

-- Rubbing your hands together to warm them up when they're cold.

-- Rubbing two sticks together to make a fire.

the working equation for the angular size is the product of the physical size and 360 degrees divided by the product of two pi and distance from earth. the minimum size would be 0.559 degrees while the maximum size would be 0.49 degrees. 

it doesn't. it was imagined up in the middle ages.