Answer to Question 1
Answer: Hanging valleys erode because the main-valley glacier is thicker than the side-valley tributary glaciers. The main-valley glacier is thicker because it gains ice from each tributary that joins it. The shear stress is higher, and the depth of erosion is greater where the ice is thicker. This means that the thicker, main-valley glacier erodes more deeply than the thinner, side-valley glaciers.
Answer to Question 2
Answer: 1) The transformation of irregular snowflakes into rounded snow grains. 2) Rounded ice grains recrystallize where high pressure exists where adjacent grains are touching. Eventually all spaces are filled with crystalline ice.