In order not to sink into the snow it is advisable to use special snow shoes which have a greater surface area of support than normal shoes. In contrast, stiletto heeled shoes deform the ground and easily sink. A blunt knife is difficult to cut with. If we sharpen it the surface area of the cutting edge decreases and it cuts more easily. The blades of an ice skate also cut into the ice.

If a force acts on a small surface, its deforming effect is large.
If a force acts on a large surface, the deforming effect is small.

The deforming power of a force is "shared out" over the surface on which it acts. The scalar magnitude which measures this "sharing out" is pressure, which is defined as the "force applied perpendicularly on each unit of surface area".

The following control takes you to the animation. First select the surface on which the block is going to rest (faces A, B, C) and start the animation. To be able to see more clearly in which cases the block sinks, click and drag on the drawing to change the prespective.

Hydrostatic pressure: click on next at the top right hand corner.