A body of rock would most likely exhibit brittle behavior under the condition of LOW TEMPERATURE.
At low temperature, the water in the crevices of the rock will freeze up, the freezing up of this water causes fractures in the rocks and as time goes on the rocks become brittle and parts of it will start falling away.<span />
If the Earth were a disk with its surface perpendicular to the rays of sunlight, each point on it would receive the same amount of radiation. <span> However, the Earth is a sphere and aside from the part closest to the sun, where the rays of sunlight are perpendicular to the ground, its surface tilts with respect to the incoming rays of energy with the regions furthest away. Hope this answers the question.</span>