The interplay of several forces and factors influence the final form of lava. This activity describes several terms introduced in this lesson.
Stress is the force applied to a body.
For example, the weight of your body is applying a stress to the seat of your chair. Strain is how a body responds to an applied stress. Rate of strain would be how quickly the cushion bows as you sit down. Stress on lava is exerted by the force of the eruption, the force of gravity, or forces exerted during cooling. Rate of strain is how quickly the flow deforms.