In the latter case the resistance is caused by dissipation of mechanical energy when the configuration or the direction of flow is sharply changed, by the formation of vortices and secondary flows as a result of the flow breaking away, by the centrifugal forces, etc.
Why do animals depend on plants. Plants give animals the food and shelter they need. Herbivores, which are plant eating animals, rely on plants to provide them with a regular source of food. They also provide shelter to may animals, both large and small.
Plants need energy to survive just like you, but they get their energy directly from the sun. Plants are producers. Producers are living things that can make their own food using air, light, soil, and water. Plants use a process called photosynthesis to make food. Only plants can produce their own food. That's why they are called producers. Animals that eat only plants are called herbivores. Herbivores are consumers because they eat plants to survive. Deer, grasshoppers, and rabbits are all consumers.