how many days hot rays from sun required to have a rock to be splitted to become an ants volume mud particle?

Answer 1

That depends on several other factors. It is not the Sun alone - but the combined effects of one or more of the agents like rain, snow, wind, gravity etc. that weathers a rock. Also it depends on the composition and structure of the rock.
Anyway, is a long process - may takes a million of year to achieve results.

Answer 2

That answer depends on whether your rock is igneous, metamorphic, or sedimentary.....my friend.