Awoman wearing snowshoes stands safely in the snow. if she removes her snowshoes, she quickly begins to sink. explain what happens in terms of force and pressure.

The purpose of snowshoes is to widen the area pressure is applied on. When you wear plain shoes, the area of distribution of force is concentrated into a small area, namely the area of the shoes you are wearing. Now when pressure is applied on snow surface, it tends to crumble. The force of you standing is concentrated on the space your shoe occupies, increasing the pressure on that specific area. 

Now when you wear snowshoes, you widen the area and the pressure is then distributed over that area lessening the force on specific points.