25. why does snow and ice linger on the ground longer on the north side of a home or building

Explanation:

In the area of the northern hemisphere , the Sun is never directly overhead more than tropic of cancer .

So the areas in the north will always find the Sun in the southern quarter of the horizon which means that the northern side of any house or building will face the least amount of  solar heat and this is the reason why the ice or snow linger longer on the north faces of a home or a building. The exact opposite of this happens in the southern hemisphere where it lingers in the southern side.