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.
Animals depend on plants for food as plants produce food and energy which animals can't, so, herbivores eat plants to get energy, carnivores eat herbivores and other carnivores for energy and omnivores eat all four, plants, herbivores, carnivores and also other omnivores for energy.
1 Water is the second factor necessary for animals to survive. 2  Make a list of different areas water can be obtained by animals. 3  Puddles, springs, streams, and ponds are places where animals can get water.  4 We've named two factors necessary for animals to survive: food and water. 5  There are two more. Omnivores can live in many places because they eat both plants and animals. 2  Have students name examples of each group. 3  List on overhead.  4 Now that we've discussed that animals need food to survive and the different types of food animals need, who can name the second factor necessary for animals to survive.