"The barrel forms"
Natural Photo displaying inertia and momentum
A "wave" reaches barreling stage when it comes in contact with shallow water. Waves are constantly going through the ocean, yet as the beach begins to slope upwards toward land, the bottom of the wave experiences the force of the beach, causing an impulse that slows it's velocity. Yet, the top of the wave still has its initial inertia, meaning it wants to stay in motion. As a result, the "lip" of the wave will eventually pitch forward, creating a barrel effect as the top of the wave shoots ahead of the bottom. This results in what we know as the waves barrel. The beginning of the formation o the barrel is happening in this picture, as the lip begins to shoot forward.
"Rock and a hard place"
Natural Photo depicting normal and frictional forces
The pictured rock in the photo seems to be in a position where it could fall at any moment. Yet frictional and normal forces prevent it from tumbling down on to the heads of passers-by. Although the rock has huge mass, therefore a huge gravitational force, this is largely offset by the force of the rock face. The rock is leaned up against the rock, and thus a massive force is exerted by the rock face, keeping it up. Yet, because the rock face is not pushing directly opposite of gravity, there is still some force that would still theoretically pull the rock down. But this is where friction comes in. The rock is "pinned" between two rock faces. Because rocks likely have a high friction coefficient, the rock is still in a static position. Between the forces of friction and normal force, the rock is kept up.
"Girl vs Dog"
Natural Photo displaying interaction of forces
In this photo, we see a girl and dog in a sort of tug-of-war. Little do they know, however, physics is dictating the situation! The dog (barely pictured) seems to have spotted a squirrel, and is pulling on the leash to go get it. However, the girl keeps him in check by pulling back on the leash. Because they are exerting equal forces in opposite directions, there is a net force of zero. So, neither of them is moving, despite the large amount of force being exerted by both the girl and the dog.
